Aces High Bulletin Board
Help and Support Forums => Help and Training => Topic started by: Muzzy on January 15, 2011, 10:40:19 AM
-
I know this has been mentioned before, but I can't find the post...
What happens to the K4 tater gun when you extend the convergence setting? I've heard talk about 'loft' but what exactly does that mean? Do the rounds curve, or do they drop less?
-
The muzzle velocity on the round never changes. So, for it to travel farther you need to put extra loft on the round. Picture throwing a baseball at 80 mph. You can't throw harder or softer. How much trajectory you put on the ball determines how far you can throw it. Want to hit something farther out? Throw it a bit higher. Same concept.
On a side note: If you have your convergence set at 600, based on what I said earlier, it will have a lot of loft on it. So on a close target, say 200m, you will actually have to aim BELOW the target because of this.
Spork
-
The theory is that if you set it at 300 you will hit the center of a target AT 300. If you set the convergence at 600 you will hit ABOVE center at 300 due to the lob. The idea is that if your pulling G's in a tracking shot you shouldn't have to lead as much.
-
So it seems, like all convergence issues, I have 3 choices.
1. I can set the convergence at the point where I find I'm getting most of my target shots in the K4, which is around 200.
2. I can set the convergence at 600 to try and improve my distance shots, compensating for loft when I take close in shots.
3. I can set for around 300 and split the difference.
Regarding option 3, at setting 300, is there much loft at 200 and is there much drop at 400?
-
You can check it using the ".target" command. On-line or off-line type .target xxx with "xxx" being the distance you want to check (400 and 200) turn your plane north steady it in level flight, and fire a burst. Reset the distance, and do it again and then check the hit patterns.
-
Me neither
-
Yes but I said this was a lazy 30mm question. :)
Seriously though, thanks very much for the answers. I'll try to put them to good use.
-
LOL!!! well set your convergence at 300 and do the test on your next climb out....you do play to fly it again don't you?
-
LOL!!! well set your convergence at 300 and do the test on your next climb out....you do play to fly it again don't you?
And waste 2-4 perfectly good taters??? Are you insane??? :D
-
So it seems, like all convergence issues, I have 3 choices.
1. I can set the convergence at the point where I find I'm getting most of my target shots in the K4, which is around 200.
2. I can set the convergence at 600 to try and improve my distance shots, compensating for loft when I take close in shots.
3. I can set for around 300 and split the difference.
Regarding option 3, at setting 300, is there much loft at 200 and is there much drop at 400?
For what it's worth, I have mine set at 350 to "split the difference" if you will.
-
I like the 200 since I try to set up close crossing shots and dont want to loft over the tar-get. Find something that works and run with it. If you try not to get into too many tail chase scenarios and work on getting the crossing shot or a windscreen filling overtake shot you will have no problems connecting taters.
-
So it seems, like all convergence issues, I have 3 choices.
1. I can set the convergence at the point where I find I'm getting most of my target shots in the K4, which is around 200.
2. I can set the convergence at 600 to try and improve my distance shots, compensating for loft when I take close in shots.
3. I can set for around 300 and split the difference.
Regarding option 3, at setting 300, is there much loft at 200 and is there much drop at 400?
Laziness will practically ensure you get a bunch of misses when it comes to gunnery, plain and simple. There's no "magic" answer to your question, so no tidbit of advice will allow you to be lazy and successful at the same time.
From an "aim-point" perspective, you have it pretty easy with a nose-mounted gun, because it's mounted so close to eye-level and the trajectory "behaves" the way you think it should. It makes the trajectory behave the way Fugitive states-
If you set the convergence at 600 you will hit ABOVE center at 300 due to the lob.
With wing-mounted guns though, his statement isn't necessarily true though. With a 600yd convergence you'd hit LOW at 300 with the F4U's .50's, for example.
What makes it difficult to get hits with the 30mm's is the time or "space" between the rounds. Due to that, having a "perfect" convergence setting, along with "perfect" aim, is far from enough to ensure hits. You also need to time your shots perfectly, unless your target is going straight away and has no apparent motion from your perspective. An absolutely perfectly-aimed shot on a crossing target will miss every single time, if you squeeze the trigger a fraction of a second too early or too late.
The three convergence options you mention are only valid for discussion assuming you have the required timing down, or are shooting at targets that appear stationary.
Assuming you're doing that, what are the merits of each of the options you list?
1- Pro's... targets are bigger when you get closer. Less time is required for the round to travel a lesser distance.
Con's... A convergence set in super close doesn't take advantage of the trajectory to it's fullest. It's like sighting-in a center-fire deer rifle at 100 yards. It work's, but isn't optimal. It leads to more guesswork at a larger variety of ranges.
2- Pro's- It'll let you aim directly at some targets at 600yds.
Con's- You may need to adjust your aim-point for every other shot distance. It may actually be harder to hit a target at 200-300 yards, than it would have been to hit one at 600 with a 300 yard convergence.
3- Pro's- It's about as good as it gets when looking for an overall "good" option for the largest range of shooting distances. Aim a little high for long shots, maybe a little low for close (but it probably won't really matter) shots.
Con's- it still won't allow for the differences you'll see in impact point for firing while in anything other than a straight and wings-level 1G configuration. Firing while banked, inverted, nose up- or nose-down, or pulling anything more or less than 1G will render your sights inaccurate.
Regardless of the convergence you choose, the beauty of the matter is that for us, any laziness you exhibit in learning about aerial gunnery is to our benefit. In the end, it means that the best, most accurate, and most truthful answer to your question is "It just doesn't matter". :devil
-
What makes it difficult to get hits with the 30mm's is the time or "space" between the rounds. Due to that, having a "perfect" convergence setting, along with "perfect" aim, is far from enough to ensure hits. You also need to time your shots perfectly, unless your target is going straight away and has no apparent motion from your perspective. An absolutely perfectly-aimed shot on a crossing target will miss every single time, if you squeeze the trigger a fraction of a second too early or too late.
I have to respectfully disagree with your post on the inference of the sensitivity of convergence. You make some good points, but ultimately, convergence has minimal importance with shooting a proper Mk108. I will list the order of importance to prove my point:
1. Shot setup. Creating a close quarters <200yd crossing shot. This gives you the best chance to hit the target consistently.
2. Firing early and in front of your target on center. He will fly through your rounds in pieces most of the time. I have to disagree with you here when you say he can easily squeeze through your rounds if not timed properly. It can happen, but it is very unlikely. The rate of fire on mk108 is around 6.5/second. It fires slow but not that slow.
3. Last comes convergence. If you are firing early, on center, and in front of your target, I'm sorry, but the probability of missing him is slim to none regardless of what your convergence is set at with this approach. Convergence will only affect the fringe shots, that aren't on center, and this is ultimately a crap shoot, since sometimes you miss high and other times you miss low.
Having said all that, I prefer 350 because it still gives me the opportunity to land a long range tater instead of just dropping dramatically at the 450yd level.
-
Right, so, uh, I think I'm just gonna go with 300.
Thanks.
:bolt:
-
I have to respectfully disagree with your post on the inference of the sensitivity of convergence. You make some good points, but ultimately, convergence has minimal importance with shooting a proper Mk108. I will list the order of importance to prove my point:
1. Shot setup. Creating a close quarters <200yd crossing shot. This gives you the best chance to hit the target consistently.
2. Firing early and in front of your target on center. He will fly through your rounds in pieces most of the time. I have to disagree with you here when you say he can easily squeeze through your rounds if not timed properly. It can happen, but it is very unlikely. The rate of fire on mk108 is around 6.5/second. It fires slow but not that slow.
3. Last comes convergence. If you are firing early, on center, and in front of your target, I'm sorry, but the probability of missing him is slim to none regardless of what your convergence is set at with this approach. Convergence will only affect the fringe shots, that aren't on center, and this is ultimately a crap shoot, since sometimes you miss high and other times you miss low.
Having said all that, I prefer 350 because it still gives me the opportunity to land a long range tater instead of just dropping dramatically at the 450yd level.
My point isn't that convergence matters much with nose-mounted guns. It doesn't. There are ways to adjust it to "make it" matter more than it should, one of which is to stretch it way out. A handicap of sorts, willingly applied.
The timing aspect though, still plays out, and gets worse the further out you fire (simply because range estimation, and estimation of projectile travel time gets more difficult). I've never looked at the specs for any gun on any German plane, so I'll just take your word for the 6.5 rounds per second rate of fire. A gun firing at 6.5 rounds per second is firing one round every .1538 seconds. By my math, a plane crossing in front of you at 250mph is moving at 340 FPS, which means it travels 53.2 feet in the time between rounds leaving the barrel. An F4U is a pretty large fighter (at 33ft 4" length), and 250 is not too fast when it comes to an estimate of speed. Plenty short to squeeze (albeit unintentionally) into a 53ft space.
That basically means that in a 90 degree crossing shot at a 250mph target, only one round really stands a chance of hitting it. The round fired before will pass in front, the round after will pass behind. That "golden" round, fired at roughly the right time, and aimed perfectly, stands about a 62% chance of hitting. If the trigger squeeze is off by .09 seconds though, it's a miss. If you're "off" by more than .09 seconds, your next perfectly-aimed round would be the one to stand a 62% of scoring a hit. Odds of a hit would be worse if the target was a smaller plane, or was crossing at a higher speed, and would drop to zero if it wasn't aimed perfectly.
Of course, there are ways to improve your odds. As you mention, getting close will help, as will reducing the crossing angle and/or speed. Setting up a situation where you can hold (and adjust) a sustained lead would be even better.
And of course, setting up a sustained lead would totally blow any importance the convergence setting has, especially with nose-mounted guns.
-
My point isn't that convergence matters much with nose-mounted guns. It doesn't. There are ways to adjust it to "make it" matter more than it should, one of which is to stretch it way out. A handicap of sorts, willingly applied.
The timing aspect though, still plays out, and gets worse the further out you fire (simply because range estimation, and estimation of projectile travel time gets more difficult). I've never looked at the specs for any gun on any German plane, so I'll just take your word for the 6.5 rounds per second rate of fire. A gun firing at 6.5 rounds per second is firing one round every .1538 seconds. By my math, a plane crossing in front of you at 250mph is moving at 340 FPS, which means it travels 53.2 feet in the time between rounds leaving the barrel. An F4U is a pretty large fighter (at 33ft 4" length), and 250 is not too fast when it comes to an estimate of speed. Plenty short to squeeze (albeit unintentionally) into a 53ft space.
That basically means that in a 90 degree crossing shot at a 250mph target, only one round really stands a chance of hitting it. The round fired before will pass in front, the round after will pass behind. That "golden" round, fired at roughly the right time, and aimed perfectly, stands about a 62% chance of hitting. If the trigger squeeze is off by .09 seconds though, it's a miss. If you're "off" by more than .09 seconds, your next perfectly-aimed round would be the one to stand a 62% of scoring a hit. Odds of a hit would be worse if the target was a smaller plane, or was crossing at a higher speed, and would drop to zero if it wasn't aimed perfectly.
Of course, there are ways to improve your odds. As you mention, getting close will help, as will reducing the crossing angle and/or speed. Setting up a situation where you can hold (and adjust) a sustained lead would be even better.
And of course, setting up a sustained lead would totally blow any importance the convergence setting has, especially with nose-mounted guns.
You just negated all of your "math" with that statement.
Spork
-
You just negated all of your "math" with that statement.
Spork
Nope. But it appears that you don't comprehend the rest. Try harder.
It doesn't matter to me what the rate of fire is exactly; I'm quite willing to use Grizz's knowledge of that.
Figure the math out on your own. Show me where it's wrong. Show me how the math shown is negated, by not looking up a spec on a gun.
-
Nope. But it appears that you don't comprehend the rest. Try harder.
It doesn't matter to me what the rate of fire is exactly; I'm quite willing to use Grizz's knowledge of that.
Figure the math out on your own. Show me where it's wrong. Show me how the math shown is negated, by not looking up a spec on a gun.
:aok
Ignorance is bliss isn't it?
Spork
-
:aok
Ignorance is bliss isn't it?
Spork
Ha! You're so coy!
The math is correct, based on the information (and example) given.
Are you saying that Grizz's RoF estimate is wrong? Maybe I'll look it up, if I get time.
Are you able to contribute anything?
-
Ha! You're so coy!
The math is correct, based on the information (and example) given.
Are you saying that Grizz's RoF estimate is wrong? Maybe I'll look it up, if I get time.
Are you able to contribute anything?
My number came from in game test, actually Sunbat tested it and told me what he recorded. Calculating the time it takes to fire all 65 taters off. I trust his means. It might be slightly off but not really a significant amount for all intents and purposes. I agree that a plane can squeeze through a pure 90 degree deflection shot, I trust your math MtnMan. However, most angles are not pure 90 degree crosses which makes it much more difficult to squeeze through. A properly set up, aimed, and placed stream of taters will destroy the aircraft 90%+ of the time.
-
:aok
Ignorance is bliss isn't it?
You are the proof. :rofl
-
My point isn't that convergence matters much with nose-mounted guns. It doesn't. There are ways to adjust it to "make it" matter more than it should, one of which is to stretch it way out. A handicap of sorts, willingly applied.
The timing aspect though, still plays out, and gets worse the further out you fire (simply because range estimation, and estimation of projectile travel time gets more difficult). I've never looked at the specs for any gun on any German plane, so I'll just take your word for the 6.5 rounds per second rate of fire. A gun firing at 6.5 rounds per second is firing one round every .1538 seconds. By my math, a plane crossing in front of you at 250mph is moving at 340 FPS, which means it travels 53.2 feet in the time between rounds leaving the barrel. An F4U is a pretty large fighter (at 33ft 4" length), and 250 is not too fast when it comes to an estimate of speed. Plenty short to squeeze (albeit unintentionally) into a 53ft space.
That basically means that in a 90 degree crossing shot at a 250mph target, only one round really stands a chance of hitting it. The round fired before will pass in front, the round after will pass behind. That "golden" round, fired at roughly the right time, and aimed perfectly, stands about a 62% chance of hitting. If the trigger squeeze is off by .09 seconds though, it's a miss. If you're "off" by more than .09 seconds, your next perfectly-aimed round would be the one to stand a 62% of scoring a hit. Odds of a hit would be worse if the target was a smaller plane, or was crossing at a higher speed, and would drop to zero if it wasn't aimed perfectly.
Of course, there are ways to improve your odds. As you mention, getting close will help, as will reducing the crossing angle and/or speed. Setting up a situation where you can hold (and adjust) a sustained lead would be even better.
And of course, setting up a sustained lead would totally blow any importance the convergence setting has, especially with nose-mounted guns.
If you don't see why your "62% of scoring a hit" is wrong, then I am not going to sit here and explain it to you. However, I guess to be fair, if you did know that it was wrong you wouldn't have posted it in the first place so :rock sir
Spork
-
My point isn't that convergence matters much with nose-mounted guns. It doesn't. There are ways to adjust it to "make it" matter more than it should, one of which is to stretch it way out. A handicap of sorts, willingly applied.
The timing aspect though, still plays out, and gets worse the further out you fire (simply because range estimation, and estimation of projectile travel time gets more difficult). I've never looked at the specs for any gun on any German plane, so I'll just take your word for the 6.5 rounds per second rate of fire. A gun firing at 6.5 rounds per second is firing one round every .1538 seconds. By my math, a plane crossing in front of you at 250mph is moving at 340 FPS, which means it travels 53.2 feet in the time between rounds leaving the barrel. An F4U is a pretty large fighter (at 33ft 4" length), and 250 is not too fast when it comes to an estimate of speed. Plenty short to squeeze (albeit unintentionally) into a 53ft space.
That basically means that in a 90 degree crossing shot at a 250mph target, only one round really stands a chance of hitting it. The round fired before will pass in front, the round after will pass behind. That "golden" round, fired at roughly the right time, and aimed perfectly, stands about a 62% chance of hitting. If the trigger squeeze is off by .09 seconds though, it's a miss. If you're "off" by more than .09 seconds, your next perfectly-aimed round would be the one to stand a 62% of scoring a hit. Odds of a hit would be worse if the target was a smaller plane, or was crossing at a higher speed, and would drop to zero if it wasn't aimed perfectly.
Of course, there are ways to improve your odds. As you mention, getting close will help, as will reducing the crossing angle and/or speed. Setting up a situation where you can hold (and adjust) a sustained lead would be even better.
And of course, setting up a sustained lead would totally blow any importance the convergence setting has, especially with nose-mounted guns.
Alright, I'll stop being a dick and explain why your math for the "golden round" is wrong.
There are several different factors that you did not account for in your example throwing your math off, which in turn negates it. When I first posted the "I've never looked at the specs for any gun on any German plane" statement negated all your math it is because of this:
Your rounds between firing is correct, but that is the only thing you got correct. When you fire a round that round has a velocity. It is that velocity that determines "when" the round impacts not only how fast the target is crossing you. That means Round Velocity plays an integral part of the equation, no? And when you said " I've never looked at the specs for any gun on any German plane" that means you do not know the round velocity. Without which, your calculation is completely inaccurate.
Another part of your equation that you failed to mention or calculate for, is your own plane's velocity. You are traveling forward as well are you not? Airplanes can't hover, obviously, so yes you are. You also will need to take that into account (your forward velocity) when you are calculating when a "hit" will occur because you have a "closure rate" between the two aircraft which, in turn, decreases the distance between the two targets for every round that is fired.
Round diameter (if it impacts/where it impacts/how much of the explosion reaches and effects the target), constantly changing angles vs. the two points of reference(you vs. your target) etc.
All of that would will need to be calculated for to get your "golden round %"
Make sense?
Spork
-
Well, Spork is correct on many points, however mtnman states to assume a 90 degree angle-off-tail for the cross shot, so that is a constant not a variable.
Also, like every statistical calculation, there is no such thing as 100% accuracy. You cannot, in life, account for every single aspect. Everything works within a system of events, nothing is singular or linear even though it can sometimes appear that way. You could, for instance, even consider the engine torque to play a role in the equation as well, but that is often overlooked because the "preciseness" doesn't matter in the end, just a common 95% level of confidence
That being said, we're getting off topic, but when stating numbers it's best to show your calculations. Even if your average troll doesn't follow it, someone else will, and you can't argue with numbers presented in fact.
Very nice thread, I've been given a bit more insight into the art of tater smashing. Keep up the help full work :salute
-
Actually, in MtnMan's example, round velocity is completely irrelevant. I should probably let you figure it out for yourself as to why you are so terribly wrong, but since I don't think you are capable, I will explain it to you. If you fire projectiles at a certain rate per second all at the same velocity, it is irrelevant at what velocity they are firing at. The gap between the bullets will not change, as the gaps are only a function of the firing rate. If you shot bowling balls out of your aircraft at 6.5 bowling balls per second at 10mph, the gaps would be equal to the gaps created by a machine gun with the same firing rate. All round velocity matters for is lead, which has nothing to do with a plane sneaking through the rounds. MtnMan was correct, you are wrong.
Make sense?
Edit:
The gaps would be different based on different speeds, I mistyped that sentence in red, however the probability of getting hit would be equivalent based on small gaps, small velocity versus large gaps large velocity.
-
Alright, I'll stop being a dick and explain why your math for the "golden round" is wrong.
There are several different factors that you did not account for in your example throwing your math off, which in turn negates it. When I first posted the "I've never looked at the specs for any gun on any German plane" statement negated all your math it is because of this:
Your rounds between firing is correct, but that is the only thing you got correct. When you fire a round that round has a velocity. It is that velocity that determines "when" the round impacts not only how fast the target is crossing you. That means Round Velocity plays an integral part of the equation, no? And when you said " I've never looked at the specs for any gun on any German plane" that means you do not know the round velocity. Without which, your calculation is completely inaccurate.
Another part of your equation that you failed to mention or calculate for, is your own plane's velocity. You are traveling forward as well are you not? Airplanes can't hover, obviously, so yes you are. You also will need to take that into account (your forward velocity) when you are calculating when a "hit" will occur because you have a "closure rate" between the two aircraft which, in turn, decreases the distance between the two targets for every round that is fired.
Round diameter (if it impacts/where it impacts/how much of the explosion reaches and effects the target), constantly changing angles vs. the two points of reference(you vs. your target) etc.
All of that would will need to be calculated for to get your "golden round %"
Make sense?
Spork
Yup, makes sense, but it's a common misconception.
The velocity of the round doesn't factor into the "time between the spaces", so to speak. It factors into the timing in how far ahead (in time and or distance, depending on how you want to look at it) of the target you'd need to aim. The distance the target will travel between the time the rounds are fired is the same regardless of the velocity of the round. The round could go ten times as fast as it does, but the target would still travel the same distance in the time between each round leaving the bore (if the RoF is the same). I can elaborate more tomorrow night if need be, but if you think it through I think you'll see it.
It's a rate of fire question, not a velocity question. Velocity would effect how much lead is required, it wouldn't effect how far the target moves between round 1 being fired, and round 2 being fired.
I didn't factor the forward progress of the 109 in, because it's really fairly negligible compared to the speed of the round. It really only makes a difference of a few percent generally. And again, it doesn't effect the distance the target travels between the time the rounds are fired. As proof, think of it like this- if you fire at a plane crossing in front of you at xxx mph, the target will travel xxx feet every x seconds. Now, fire your guns forward while that plane crosses behind you... How far does he travel in the time between the rounds being fired? The same distance as he would if he was in front of you, or beside you, or under you...
The other reason I didn't factor in a whole multitude of things into the equation is that almost all of them reduce the likelihood of a hit. There are really only a few things you can do to improve your chances of a hit, whereas there are a whole lot of things that make your chances worse. In reality, the stationary, "rock-solid" firing platform, vs the pure 90 degree crossing shot on a known-speed, known-size, and known-distance target is as good as it gets. Forward motion of your plane also has negative connotations when it comes to aiming, especially in a situation where closure is high, and required lead is great. It'll reduce your chances of a hit almost invariably, because it makes estimation (which ties to lead calculation) more difficult. Your first shot fired is the generally your best-aimed shot. When it fails, and you need to re-adjust, you'll now have less time and a different set of variables to contend with. Of course, the target is a little bigger...
Look at the 62% estimate, and then consider the arguments (although I agree that they do have merit). The argument seems to be that 62% isn't a high enough probability of a hit? In reality, how high is the probability of a hit by any 30mm round fired? 62% is ridiculously high... If the best 109 pilot in the game counts his 30mm hits for a week or a month, or whatever, what % will be hits? Is anyone holding a 62% hit% with the 30mm's? Why not?
-
Grizz it does matter what speed they're flying at. That and the rate of fire decide how large the gaps are between each round, and how fast a target needs to be flying relative to the bullet stream to slip thru those gaps untouched.
If you're firing more than one round, it probably means you aren't near 100% sure of your aim & timing, so right away hitting's up to chance, ie probability. Rate of fire then matters if the gun's ROF is low enough that the target could fly thru the stream, e.g. 2 taters fired just so the first passes in front of target nose and the second right behind its tail.
The gaps are a function of both firing rate and relative speeds. Imagine running thru rain: with rain pouring down normally, then with rain stopped (like running thru one of those Matrix scenes where time's stopped), then with rain pouring down at near infinite speed. And all three again with varying raindrop density. Each one gives you different probabilities of getting wet / running around the raindrops without getting wet.
More on topic - changing convergence on a low velocity round like the MK108 can really get in the way of a low/medium experience player when you shoot at very high speed. You can see this easily if you take a 262 offline and shoot long bursts of all guns at 550mph+. Do it once with short convergence, then again with long convergence. At high speed, the rounds will travel much further (since their velocity isn't just muzzle velocity but MV + the plane's very high speed) before bending back down.
And then it's even less intuitive when you shoot near vertical angles, or inverted.
Mtnman - 62% meaning chance the pilot aimed and timed on target, or 62% chance a perfectly aimed/timed shot will hit due to dispersion?
-
ummmmmm shall we say "schooled" :D
Well posted, and explained gentlemen.
-
Grizz it does matter what speed they're flying at. That and the rate of fire decide how large the gaps are between each round, and how fast a target needs to be flying relative to the bullet stream to slip thru those gaps untouched.
I don't think so dude. The size of the gaps are proportional to the velocity. The two factors effectively cancel one another out. If you fired bowling balls at 10 per second, their velocity would be incredibly low but their gap would be very tight. If you fired 50 cals at 10 per second, the velocity would be incredibly high but their gap would be very wide. The two are linearly proportional. Ultimately, the only thing velocity affects is lead.
As for your matrix example, that would be a function of your target's speed, not the speed of the bullets. In other words, a target with X velocity has the same probability of squeezing through a stream of 2 bullets spaced z feet apart traveling y mph as he would 2 bullets spaced 2*z feet apart traveling at 2*y mph.
Edit: We are saying the same thing. I misconstrued what I was trying to say in my initial post. In a nutshell, all that matters is the rate of fire.
-
I got a golden bullet today....got a kill with the tater at -400....so, like, it's possible, right?
Okay I'm leaving again. :bolt:
-
Bullet speed, target speed, same difference: relative velocity's a factor in hitting if we're talking MK108. E.G. firing a prophub 108 at a 262 running away vs. firing it at a brewster flying almost head-on. On those kind of targets where the time window for a shot is smaller (quicker) than the gun's rate of fire, it does matter what speed the bullets are flying.
(http://farm6.static.flickr.com/5041/5365661473_7096cb9614_o.jpg)
Which one lands more hits?
1) bullet stream flying at 2mph
2) bullet stream flying at 2000mph
And for the 108, higher speed means denser bullet cloud for target to fly thru, which means higher probability that it'll connect.
In my experience, and that's what we oughta be arguing - not just theory with no practical value - the 108 is slow and decelerates enough that it is a factor you can't neglect in making shots. The running 262's an extreme example, but unless my memory's bad, everyday circumstances are enough for 108 shots that without a doubt are aimed perfectly to not connect because the target flies right thru those gaps. Solution is either firing shallower angles (superposes more of the bullet stream over target as target crosses it), or tracking the target as you shoot - e.g. with a jink like I did in that long-ish 262 snapshot.
If you're firing from pretty far out where the 108 rounds have slowed way down, it's about as bad as it gets and then you've got not just big gaps due to low ROF, but slow bullets that in the most extreme cases you can literally dodge: e.g. when target's flying so fast that it can see bullets limping along and timing out. You see this all the time e.g. when extending in a 262 with a flock of sprayers 1K back.
-
Which one lands more hits?
1) bullet stream flying at 2mph
2) bullet stream flying at 2000mph
If they fire at the same ROF, then the probability of landing hits will be equal.
Rounds will also deaccelerate at the same rate regardless of their initial velocity and will "fall" at the same rate in the y direction regardless of their initial velocity. Velocities come into play when we are talking leads, horizontal and vertical, but the basis of this debate was assuming you lead correctly and the target was flying through your perfectly placed rounds. Clearly bullets with a higher rate of initial velocity are easier to aim with.
-
That blue target isn't stationary.
-
I got a golden bullet today....got a kill with the tater at -400....so, like, it's possible, right?
Okay I'm leaving again. :bolt:
Hit a tater at 800 before so yes it is possible. Although I do not know the max range of the 30mm.
-
That blue target isn't stationary.
Irrelevant, the gaps between the bullets firing at 2mph are very small, the gaps between the 1000mph are very large.
Edit: In your illustratiion the higher velocity rounds will hit with higher probability only because your illustration does not take into account the disparity in the gap size based on the firing velocity.
-
If they fire at the same ROF, then the probability of landing hits will be equal.
This is true. The leads must be adjusted but the probablity of hitting should be the same since the lack of velocity is corrected by the close spacing of the slower bullets. It's critical to remember that the leads must be correct in both instances to make a fair comparison.
-
I can't picture it anymore. Gonna have to do it with math.
I think incorrect aim and timing is important to consider in this argument because most people have imperfect aim, esp. with the 108.
Edit: In your illustratiion the higher velocity rounds will hit with higher probability only because your illustration does not take into account the disparity in the gap size based on the firing velocity.
Yes, rate of fire means how long each gap lasts, and varying speed but equal ROF means target should end up with the same amount of time to sneak thru.
But I had something else in mind and now I can't remember what it was.
-
I can't picture it anymore. Gonna have to do it with math.
I think incorrect aim and timing is important to consider in this argument because most people have imperfect aim, esp. with the 108.
Yes, rate of fire means how long each gap lasts, and varying speed but equal ROF means target should end up with the same amount of time to sneak thru.
But I had something else in mind and now I can't remember what it was.
You are exactly correct they should be considered for aiming. This was just a fun silly theoretical debate working under the premise that the bogey is flying through your rounds. That works off the assumption that the lead and accuracy is perfect. Actually lead doesn't have to be perfect, it just has to be out in front. If you are going to error, error on the side of too much lead, as you already know.
-
But lead and accuracy aren't perfect in practice, so it is pertinent for this thread's purpose.. It's in the help forum.
I figured out what bothered me about this. Bullet speed matters because the target has volume; it's a separate thing from considering gaps between bullets: If the target has volume, the bullet crossing its path (meaning the volume of space that the target will occupy that coincides with the bullet stream) will take an amount of time directly proportionate to its speed, to cross that volume. IOW the bullet will be present inside that volume which the target has to displace (that coincident volume of target body moving thru bullet stream and volume of bullet stream itself) as it moves thru stream, for longer.
The faster the bullet, the nearer zero the time it takes to cross the target's volume, and the smaller your margin for aiming (not timing) error that's accommodated by the bullet lingering longer in the target's path. Which is totally counter intuitive.. Reality check says: the faster your bullet (regardless ROF), the less you need to lead, the easier it is to aim and time the shot.
I need to sleep.
-
Hit a tater at 800 before so yes it is possible. Although I do not know the max range of the 30mm.
135 foot drop at 1000 meters.
If you look at the armorers diagrams in the german manuals, 400 meters was the maximum they concidered effective. That was a 12ft drop at 400 meters. And unlike in AH the motorkanone does not tilt up through the engine as you set the convergence in the hanger to lob over your LOS to perfictly drop your 30mm in the center of your gunsight and offline target. The closest you will ever get with the current gunnery model to the real world motorkanone mounted balistics is to set all of your 109, Ta152, Yak and P39 nose cannon back to 150 yards.
The round dropped straight out of the spinner. The Revi graticule was raised up to see a point on a board 100 meters away 29cm below the 0-datum line of the engine through the spinner. Then you used the bottom stadia mark on the cross hair or the bottom of the circle as your straight line indicator of an impact point 30.745 meters(12ft) low at 400 meters with the 30mm.
Page 15 shows the screw (21)Hohen which adjusts for the H value in the balistics table for the Visierlinie@100m. It tilts a mirror to raise and lower the graticule.
http://deutscheluftwaffe.de/archiv/Dokumente/ABC/r/Reflexvisiere/Revi%2016%20B%20Waffenhandbuch.pdf
Page 24 for the actual balistics of the 30mm out of a 109 spinner.
http://deutscheluftwaffe.de/archiv/Dokumente/ABC/m/Messerschmitt/Me%20109/Bf%20109%20G-6%20U4%20Bedienungsvorschrift%20-Wa.pdf
By the way the MG151/20 motorkanone dropped 43 inches at 400 meters and 13.6 feet at 710 meters out of the spinner. All guns on the 109's were set to ballisticaly follow the motorkanone to effectivley group the rounds.
-
I have to run to work, be back in about 15 hours...
Anyway, a few thoughts-
Bullet stream isn't straight... This means the gap between the bullets isn't the same size. They also can't be any closer together in time, so the gap would be closest for two rounds fired while the firing plane is going straight forward with no G's pulled. That would create a .15 second gap between rounds.
Any change in G's will effect that by making the gap between bullets larger, because it would then be a gap of (time plus space). Think of a big "S" shaped or "C" shaped shot stream.
Also, the thought of a "stream" is a misnomer. A stream of 10 rounds is really 10 individually aimed/fired rounds, all of which may be (and probably are) happening under different conditions (G's, bank angle, range, etc).
Lastly, convergence. What we're looking for with convergence is the best setting for the most circumstances. Look up "Point blank" sighting-in strategies for sighting in a deer rifle. That's what you'd want, but applied to the 30mm with a larger target.
-
I have to run to work, be back in about 15 hours...
Any change in G's will effect that by making the gap between bullets larger, because it would then be a gap of (time plus space). Think of a big "S" shaped or "C" shaped shot stream.
If you can get larger gaps then you can get smaller gaps if target is moving and you aim/time burst just right.
Also, the thought of a "stream" is a misnomer. A stream of 10 rounds is really 10 individually aimed/fired rounds, all of which may be (and probably are) happening under different conditions (G's, bank angle, range, etc).
Yes but only if they're under those differing conditions.
-
I used a larger plane size(remembered incorrectly what ya used) but our numbers are the same mtnman. Where did Spork go?
(http://i379.photobucket.com/albums/oo237/grizz441/taterphysics.jpg)
-
lol @ all this just point and click when it feels good
-
I think the math was over Spork's 5th grade math. :)
-
So you guys are happy with your HUB mounted 30mm being angled to shoot up through the engine in the game to achive the distance you pull the convergence line out to so you can fire the round over your line of sight and drop it perfictly into the center of the target?
I have provided you the real world data that shows this is impossible and was never implimented in this manner in any german fighter while it was mounted in the engine. I was hoping to get more than a crickett gallery from some of this games Avatars of skill and gamemanship before I wishlisted this obvious technical error. I've seen several of this audience argue in these forums over real world performance tech data with a vengence.
What is different in this case??
It's not like I'm trying to argue performance numbers from 6 different sources with 6 different values. All of the 109 armerors manuals show the same balistics for the motokanone with the 20mm and the 30mm mounted. HUB firing cannons are fixed in place and the round drops under the nose out of the spinner. I even found pictures of the Yak's VK-105PF. Looks like the 20mm is strapped in to fire center of the hollow airscrew reduction tube. http://en.valka.cz/viewtopic.php/t/54646
Page 60 109F MG151/20
http://deutscheluftwaffe.de/archiv/Dokumente/ABC/m/Messerschmitt/Me%20109/Bf%20109%20%20F-2%20F-4%20Wa.pdf
Page 23 MK108.
http://deutscheluftwaffe.de/archiv/Dokumente/ABC/m/Messerschmitt/Me%20109/Bf%20109%20G-6%20U4%20Bedienungsvorschrift%20-Wa.pdf
Page 30 MG151/20.
http://deutscheluftwaffe.de/archiv/Dokumente/ABC/m/Messerschmitt/Me%20109/Bf%20109%20G-5%20G-6%20Wa.pdf
Or you can translate the relevent section where the armorer is told the motorkanone is fixed mounted parallel to the line of the engine.
-
What is different in this case??
Gameplay? Like flaps not modeled as real ones (self-retract). I personally wouldn't care either way. I don't think it'd be hard to adapt to.
-
I think the math was over Spork's 5th grade math. :)
:aok
Everything I have been saying is being confirmed by Moot and now Grizz with his math. I was stating from the very beginning that mtnman's math was wrong and the 63% "golden round" was wrong. Now Grizz "showed" his math and he got 97% also, you guys aren't thinking three dimensionally. We do not fight on a 2D plane.
Spork
-
The bottom line isn't what the bullet stream itself looks like, but what it looks like from the target's reference frame.
I want to script something to show what does what (rof, speeds, angle, tracking, etc) with a little graphics app, but I don't know how to write code that well yet. I'll do it once I do know.
-
Gameplay? Like flaps not modeled as real ones (self-retract). I personally wouldn't care either way. I don't think it'd be hard to adapt to.
Probably not hard at all. You would have to remember your round drops away faster than ever before at closer engagement distances if HiTech recoads the motorkanone and cousins. Testing offline with the cannon at 150 the best percentage hit range with the MK108 was at 100-250+- for fighters. 400+- for bombers which fits with the german tech expectations for the ballistics of the MK108 30mm.
HiTech can change the flaps to non-auto in moments and let us rip them off for awhile. Might change the predator pyramid in the game for a tour or two. The angery posts in here would be entertaining.
But, a whole technological family of wheapons systems being modeled to fire in a manner physically impossible in the face of the evidence. A bit gamey beyond auto flaps and definately training wheelish with pink handel bar tassels even for the Grizzinator. Or have the muppets been aware of this discrepency all along and not mentioned it to anyone?
Sorta as gamey as the fact our K14 is being presented to us in "Locked" mode which means we should have either a ring and dot centerd over the left paralax lens or a 6-pointed star and dot centerd over the right paralax lenz. Only if the MK8, N3 or N9 gunsight is used do you get a centered graticule in a P51.
-
:aok
Everything I have been saying is being confirmed by Moot and now Grizz with his math. I was stating from the very beginning that mtnman's math was wrong and the 63% "golden round" was wrong. Now Grizz "showed" his math and he got 97% also, you guys aren't thinking three dimensionally. We do not fight on a 2D plane.
Spork
The only reason MtnMan's and my math differed was being I used a different plane length. Had I used his plane length the probabilities would be equal. MtnMan's math was not incorrect.
The way we are idealizing the problem works fine for 2D. I was also going to post a sketch of how "throwing your nose" parallel to the bogey as you fire taters increases the probability of a connection, but I ran out of time today. It would be more difficult as well.
-
So you guys are happy with your HUB mounted 30mm being angled to shoot up through the engine in the game to achive the distance you pull the convergence line out to so you can fire the round over your line of sight and drop it perfictly into the center of the target?
I have provided you the real world data that shows this is impossible and was never implimented in this manner in any german fighter while it was mounted in the engine. I was hoping to get more than a crickett gallery from some of this games Avatars of skill and gamemanship before I wishlisted this obvious technical error. I've seen several of this audience argue in these forums over real world performance tech data with a vengence.
What is different in this case??
It's not like I'm trying to argue performance numbers from 6 different sources with 6 different values. All of the 109 armerors manuals show the same balistics for the motokanone with the 20mm and the 30mm mounted. HUB firing cannons are fixed in place and the round drops under the nose out of the spinner. I even found pictures of the Yak's VK-105PF. Looks like the 20mm is strapped in to fire center of the hollow airscrew reduction tube. http://en.valka.cz/viewtopic.php/t/54646
Page 60 109F MG151/20
http://deutscheluftwaffe.de/archiv/Dokumente/ABC/m/Messerschmitt/Me%20109/Bf%20109%20%20F-2%20F-4%20Wa.pdf
Page 23 MK108.
http://deutscheluftwaffe.de/archiv/Dokumente/ABC/m/Messerschmitt/Me%20109/Bf%20109%20G-6%20U4%20Bedienungsvorschrift%20-Wa.pdf
Page 30 MG151/20.
http://deutscheluftwaffe.de/archiv/Dokumente/ABC/m/Messerschmitt/Me%20109/Bf%20109%20G-5%20G-6%20Wa.pdf
Or you can translate the relevent section where the armorer is told the motorkanone is fixed mounted parallel to the line of the engine.
I do not know enough about the ballistics of the real deal to really comment. I am looking into it now though. If it changes for whatever reason not a big deal I set my cannon at 225.
Maybe you should post it in the wishlist so we don't further hijack this thread. I have a feeling it will stir some people up.
-
:huh
So like, 300 convergence is good, right?
-
Put it wherever you most often take your shots. After using it for a while, adjust from that setting as needed.
-
So you guys are happy with your HUB mounted 30mm being angled to shoot up through the engine in the game to achive the distance you pull the convergence line out to so you can fire the round over your line of sight and drop it perfictly into the center of the target?
I have provided you the real world data that shows this is impossible and was never implimented in this manner in any german fighter while it was mounted in the engine. I was hoping to get more than a crickett gallery from some of this games Avatars of skill and gamemanship before I wishlisted this obvious technical error. I've seen several of this audience argue in these forums over real world performance tech data with a vengence.
What is different in this case??
It's not like I'm trying to argue performance numbers from 6 different sources with 6 different values. All of the 109 armerors manuals show the same balistics for the motokanone with the 20mm and the 30mm mounted. HUB firing cannons are fixed in place and the round drops under the nose out of the spinner. I even found pictures of the Yak's VK-105PF. Looks like the 20mm is strapped in to fire center of the hollow airscrew reduction tube. http://en.valka.cz/viewtopic.php/t/54646
Page 60 109F MG151/20
http://deutscheluftwaffe.de/archiv/Dokumente/ABC/m/Messerschmitt/Me%20109/Bf%20109%20%20F-2%20F-4%20Wa.pdf
Page 23 MK108.
http://deutscheluftwaffe.de/archiv/Dokumente/ABC/m/Messerschmitt/Me%20109/Bf%20109%20G-6%20U4%20Bedienungsvorschrift%20-Wa.pdf
Page 30 MG151/20.
http://deutscheluftwaffe.de/archiv/Dokumente/ABC/m/Messerschmitt/Me%20109/Bf%20109%20G-5%20G-6%20Wa.pdf
Or you can translate the relevent section where the armorer is told the motorkanone is fixed mounted parallel to the line of the engine.
Start a new thread in aircraft and vehicles or wishlist and I'll be happy to look at it. I'd be interested in seeing a side profile of A k4 showing where the hub cannon is located in relation to the prop and doing the math myself to see if a tater lobbed up to a desired long convergence will in fact hit its own engine. I am too tired and lazy to read all the off topic links right now.
-
If you can get larger gaps then you can get smaller gaps if target is moving and you aim/time burst just right.
You can get smaller gaps in space, but not in time, and it's easy enough to do. To do it, you don't fire at a crossing target.
A crossing target maximizes the spacial effect, to the 55 feet or so that Grizz and I came to. The faster the target appears to be moving, (while you don't change heading) the larger the spacial "gap" effect. At a given speed, a 90 degree crossing target has the highest apparent speed possible, so it maximizes the the effect of time between rounds.
On the other hand, firing at a target that appears motionless (directly in front of you, going directly away or directly towards you) would minimize the spacial effect. In effect, it nullifies the effect of time between rounds.
And each shot in the stream is fired under differing conditions in a crossing shot (even if it isn't a 90 degree deflection). The range is different, the angle up/down may be different, G's may be different. The target's in a different spot. An aim that's perfect for a fraction of a second will be terribly wrong a fraction of a second later, because the conditions are no longer what they once were...
-
:aok
Everything I have been saying is being confirmed by Moot and now Grizz with his math. I was stating from the very beginning that mtnman's math was wrong and the 63% "golden round" was wrong. Now Grizz "showed" his math and he got 97% also, you guys aren't thinking three dimensionally. We do not fight on a 2D plane.
Spork
As Grizz mentioned, we came to a different Hit% probability because he used a longer target aircraft than I did. I used a 33ft fighter as a model, which is close for an F4U, Spit, or P51. If you chose an aircraft that was larger than 55ft, you'd up your chances to 100%, or even open up the possibility that the target could now get hit by the first round, and the next round to come along, if the first round hit the front of the target.
On the other hand, if the target was smaller, say 25ft, the chance would drop to 50%. If it was 12.5 ft, the chance drops to 25%.
And again, we're talking about a perfectly aimed shot, for arguments sake.
Apart from the target size, the chance of a hit also changes with the speed of the target. If the speed of the crossing target doubled, the "gap" would double to 110 ft. The 33ft targets chances of being hit would be 31% now...
Also, keep in mind that in stream of rounds from a gun firing as we've modeled, in the situation modeled, only one of the rounds would have any chance at all of hitting. Say you fired a ten-round stream... If the aim was perfect, and the timing was correct for the 6th round to connect, the other nine would be misses. The chances would be 0% for the other rounds, 100% for the 6th round.
-
Also, keep in mind that in stream of rounds from a gun firing as we've modeled, in the situation modeled, only one of the rounds would have any chance at all of hitting. Say you fired a ten-round stream... If the aim was perfect, and the timing was correct for the 6th round to connect, the other nine would be misses. The chances would be 0% for the other rounds, 100% for the 6th round.
Which is why the best tatering strategy is to fire out in front and have the target fly through them. I also prefer a slight rudder swing as I fire the taters which I believe increases the probability if you throw the nose at the proper angular velocity. Caveat: This is for close shots with full profile. Rudder throwing causes more inaccuracy in alignment. Maybe I'll show mathmatically this weekend why throwing your rudder will actually increase the probability of a connection.
I remember one crazy tater shot I hit on you mtnman, it was from the side, you were going about 400 maybe a 70 degree crossing shot but you were never looking at me. My entire focus was on an imaginery line way out in front of your line of action and hoping I lined it up correctly.
-
The real point of all this was to answer the OP's question, right? And why would someone be looking for an effective convergence setting, apart from looking for a way to score some hits?
In reality, a "mid" range convergence would prove to be the best all-around, general purpose setting, if you went through a bunch of testing. Trust me, I've done a LOT. I've also done a ton of real-world shooting, with a variety of firearms in a variety of conditions/settings. Personally, I'd go with a 300yd or so convergence, and I'd throw away the convergence-setting key at that point. I'd learn to use the guns like that. "Knowing" what they'll do comes with lots of practice.
A close setting will maximize your effectiveness at close range, but reduce it at the other ranges (where you're more likely to shoot anyway). Same goes for a long-range convergence. At long-ranges, dispersion alone messes things up, so even a shot at convergence distance isn't as effective as it could be...
Of course, that argument is somewhat nullified by the fact that the gun is nose-mounted near eye-level (which makes gunnery much simpler) and the fact that it only takes one hit to do serious damage.
The nose-mounting, and effectiveness of the round, should make this an easy gun to master. Why do so many have trouble with it then? RoF for one... Velocity seems likely as well, but I haven't bothered to look it up yet.
-
I remember one crazy tater shot I hit on you mtnman, it was from the side, you were going about 400 maybe a 70 degree crossing shot but you were never looking at me. My entire focus was on an imaginery line way out in front of your line of action and hoping I lined it up correctly.
Ha! I remember that! Not like I could forget it, lol...
I'd be willing to bet though, that your strategy for the most part is to line up on a point in front of your target, relax on the controls, and fire a short burst a tad early? If it misses, set it up again? Rather than firing on a curving turn, you're flying more of a "stop-sign" circle, firing on the "flats"? Pull, relax, fire, pull, relax, fire?
In effect, that's treating the guns almost like single-shot weapons, even though we benefit from the "stream" aspect, which can correct for miss-judged timing?
That's basically what I do... There are times when I'll pull hard and squeeze, but for those I'm sure of a hit, and I know it. Close in, slow target (even if it's crossing) and I can hit it even if I'm blacked-out.
Now, on sustained lead shots, I'd guess you'll hose 'em down too (or walk your rounds on target), but I'd wager you don't often fire sustained bursts while holding much pressure on the elevator?
The reason I ask is because what so many seem to do is think there's a "magic" convergence setting, that makes up for "something", and they experiment looking for it thinking when they find it it'll solve their gunnery qualms.
I'd guess most of the better shots in the game don't screw around with it much though. They rely on a (or a few) simple technique(s) to score hits, rather than looking for a magic setting.
-
Yep, find a convergence setting that's comfy - that puts the rounds where you most often want/need em - and fly around any of that convergence setting's shortcomings.
-
Well 300 seems to work for me. I've gotten 2 kills out at 400 with no trouble on that setting.
-
Then this as a technical simulation seems to be much less concerned about faithfull accuracy at one of the two ends of some wheapons systems since there is no mechanical way to set the elevation above 0-datum motor line with the MK108 or MG151/20 in any motor cannon mounted aircraft Germany produced. At this stage in HiTech's coading genius I doubt he would have any trouble revamping the affected wheapons systems to the manufacturers mounting specifications.
But, again maybe HTC has never had the manuals translated I'm refrencing since there is so much english language translated and post WW2 U.S. government technical data available to coad these systems with. And it seems this audience is vested completely in the results of sticking the pointy stick in the mammoth, in this mammoth hunting simulation, rather than the process behind the pointy stick getting there is a narrow focus worm hole rather than direct arm power.
BFG9000, Chain guns and particule beam sniper rifles anyone?
-
MK108 & MG151 aren't nearly turned into wonder weapons due to convergence freedom. Or I'm misreading you.
-
Did not think that convergence was that big of a deal.
-
The only reason I asked was because in-game, I know the 30mm tends to do strange things depending on where convergence was set. I've heard arguments about whether to set it at 200, 300 or all the way out to 600. Turns out 300 was right for me, so...
But wow...didn't mean to spark all this debate and discussion, interesting as it was.
-
The only reason I asked was because in-game, I know the 30mm tends to do strange things depending on where convergence was set. I've heard arguments about whether to set it at 200, 300 or all the way out to 600. Turns out 300 was right for me, so...
But wow...didn't mean to spark all this debate and discussion, interesting as it was.
And that's actually what I'm interested in...
What "strange things" does it do? Why are they "strange", and how does the convergence setting effect it?
I don't fly the 109's much at all. By far the most experience I have with it is in the TA, when I've been asked to teach folks in it. But... I've never found it to do anything "strange" gunnery-wise, and haven't found it to be tough to hit anything with, or had trouble getting kills with it in the MA when I've occasionally flown it.
Are the "strange things" really occurring at all? If they are, are they really related to convergence? Or, are they related to something else, but blamed on convergence? Maybe a general misunderstanding of what's going on is leading to the blame being directed where it doesn't belong.
I think we need a list of strange 30mm things so we can investigate...
-
The shells have a bit of an arc to them. They hit dead on at convergence, but closer in they tend to be high, and further out they drop. I experienced this recently while trying to bag a Yak at 400 out. I fired a shell with my sights set slightly above the target and got a dead-on hit.
-
The shells have a bit of an arc to them. They hit dead on at convergence, but closer in they tend to be high, and further out they drop. I experienced this recently while trying to bag a Yak at 400 out. I fired a shell with my sights set slightly above the target and got a dead-on hit.
This is nothing "strange". This is happening to all guns, it's just more pronounced with the MK-108 because of it's relatively low muzzle mvelocity.
-
This is nothing "strange". This is happening to all guns, it's just more pronounced with the MK-108 because of it's relatively low muzzle mvelocity.
:aok What he says.
-
The shells have a bit of an arc to them. They hit dead on at convergence, but closer in they tend to be high, and further out they drop. I experienced this recently while trying to bag a Yak at 400 out. I fired a shell with my sights set slightly above the target and got a dead-on hit.
That's not strange though, that's what would be expected by anyone who's shot a rifle (assuming you have your convergence set inside 400).
Nose-mounted guns shouldn't do anything remotely "strange" as guns mounted well below the LoS, and/or out on the wings. If you combined "well below the LoS and "out on the wings", then I could certainly see how people would be confused.
In my F4U with a 300yd convergence, I see the opposite effect as you describe. My rounds are low closer-in, and slightly high at 400... With a closer convergence, it's even worse! With a 150yd convergence, I'm still low closer-in, but I'll actually miss a 600yd shot because my rounds are so high they'll go right over it (and pass over or outside his wingtips too, if I aim at his tail). I'd actually shoot over a target at 300yds with a 150yd convergence, which is polar opposite of what most would assume.
Wing-mounted guns are much more confusing (and critical) when it comes to convergence. Which is one reason why someone would go through the trouble of figuring out a way to mount the guns in/on the fuselage, even if it meant running it through the engine, or firing between the propeller blades. The forgiveness the nose-mounted guns offer for firing while banked, and because they're so much closer to the LoS is significant too.
I'm actually tempted to go map out the 30mm convergences now.
-
can someone shrink grizz's physics equation picture to avatar size so that i may enjoy it more frequently? oh yeah an why would you need to set a convergence on a gun that shoots straight out the nose of a plane?
-
oh yeah an why would you need to set a convergence on a gun that shoots straight out the nose of a plane?
Because convergence is vertical as well as horizontal. Even though no left to right adjustment would be necessary when a gun is fired directly out the center of the aircraft, you will still need to "lob" the projectile (depending on the mass and the velocity of that projectile) to hit between the cross hairs at your convergence distance. The heavier and slower the muzzle velocity, the more "lob" that would need to be put on a projectile to hit the target at any given distance. This is further exacerbated by setting the convergence out to a longer distance, the projectile has to be lobbed even higher to compensate for the drop due to gravity.
<S>
Edgar
-
taterphysics avatar
(http://www.vmf-222.com/taterphysics_avatar.jpg)
-
ah i see. well at risk of sounding luft-noobish i guess that means the shorter the convergence, the higher up the 30mm points? right now i have my head position all the way up on the k4 and convergence set at 650. it works, but dead 6 i always have to aim at the top of the enemies cockpit to get a direct hit. i think its my head position but it could be the 650 convergence
-
ah i see. well at risk of sounding luft-noobish i guess that means the shorter the convergence, the higher up the 30mm points? right now i have my head position all the way up on the k4 and convergence set at 650. it works, but dead 6 i always have to aim at the top of the enemies cockpit to get a direct hit. i think its my head position but it could be the 650 convergence
Shorter the convergence, the lower the 30mm points, and the higher you have to point it.
-
ah i see. well at risk of sounding luft-noobish i guess that means the shorter the convergence, the higher up the 30mm points? right now i have my head position all the way up on the k4 and convergence set at 650. it works, but dead 6 i always have to aim at the top of the enemies cockpit to get a direct hit. i think its my head position but it could be the 650 convergence
Grizz is right, you should need to aim low, not high. Your head position should make you shoot high, too, so you should really need to aim low.
It seems odd that you'd need to aim at the top of his cockpit.
-
The reason you shoot high is because physics works that way: velocity in each dimension is independent. A flying bullet will drop to the ground as fast as one dropped out of your hand. The only difference is how far forward the flying one goes. And if you decompose any shot's angle, you get separate vertical and horizontal components, where 45deg happens to be the initial angle (the combination of initial horizontal and vertical velocity) where a bullet will land furthest.
(http://farm6.static.flickr.com/5212/5385907376_89af75ec29_o.gif)
http://hyperphysics.phy-astr.gsu.edu/hbase/traj.html#tra12
-
i dont think i shoot far enough out in the k4 or g14 for physics to be a factor. i shoot just before the area where if you fire the tater explosion will kill you. sounds like the line of sight between my head position and the gunsight is not intersecting the vector of the tater where i think it is. i will play around with it based on this new information you all have given me. thanks
-
I have to respectfully disagree with your post on the inference of the sensitivity of convergence. You make some good points, but ultimately, convergence has minimal importance with shooting a proper Mk108. I will list the order of importance to prove my point:
1. Shot setup. Creating a close quarters <200yd crossing shot. This gives you the best chance to hit the target consistently.
2. Firing early and in front of your target on center. He will fly through your rounds in pieces most of the time. I have to disagree with you here when you say he can easily squeeze through your rounds if not timed properly. It can happen, but it is very unlikely. The rate of fire on mk108 is around 6.5/second. It fires slow but not that slow.
3. Last comes convergence. If you are firing early, on center, and in front of your target, I'm sorry, but the probability of missing him is slim to none regardless of what your convergence is set at with this approach. Convergence will only affect the fringe shots, that aren't on center, and this is ultimately a crap shoot, since sometimes you miss high and other times you miss low.
Having said all that, I prefer 350 because it still gives me the opportunity to land a long range tater instead of just dropping dramatically at the 450yd level.
MK 108 cannon
From Wikipedia, the free encyclopedia
The MK 108 machine cannon
Type Autocannon
Place of origin Germany
Service history
In service 1943–1945
Used by Nazi Germany
Wars World War II
Production history
Designer Rheinmetall-Borsig
Designed 1940
Manufacturer Rheinmetall-Borsig
Produced 1943–1945
Specifications
Weight 58 kilograms (130 lb)
Length 1,057 millimetres (41.6 in)
Barrel length 23 inches (580 mm)
Cartridge 30×90RB mm steel casing
Caliber 30 mm
Action Blowback operation
Rate of fire 650 rounds/min :headscratch:
Muzzle velocity 540 m/s (1,770 ft/s) :headscratch:
The MK 108 (German: Maschinenkanone—"machine cannon") was a 30 mm caliber autocannon manufactured in Germany during World War II by Rheinmetall-Borsig for use in aircraft.
The weapon was developed as a private venture by the company in 1940 and was submitted to the Reichsluftfahrtministerium (RLM—Reich Aviation Ministry) in response to a 1942 requirement for a heavy aircraft weapon for use against the Allied bombers appearing en masse in German skies by then.
>>>>>>>>>>>>>>THIS IS WHAT CAUGHT MY ATTENTION THE MOST WAS THE AMOUNT OF 20MM IT TOOK TO SHOOT DOWN BOMBERS<<<<<<<<<<<<
Testing verified that the autocannon was well-suited to this role, requiring on average just four hits with high-explosive ammunition to bring down a heavy bomber such as a B-17 Flying Fortress or B-24 Liberator and a single hit to down a fighter. In comparison, the otherwise excellent 20 mm MG 151/20 required an average of 25 hits to down a B-17.
The MK 108 was quickly ordered into production and was installed in a variety of Luftwaffe fighter aircraft. It saw first operational service in late autumn 1943 with the Bf 110G-2 bomber destroyers and in the Bf 109G-6/U4.
[edit] Design details
[edit] Ammunition
The cannon used specially-developed 30×90RB mm ammunition—30 mm calibre, 90 mm case length, rebated/reduced rim. Unlike most other weapon rounds, which used traditional brass for the case, the MK 108's ammunition used steel cases. Several types of ammunition were developed, including practice, armor-piercing, high-explosive and incendiary. In operation, however, two major ammunition types were used: Minengeschoß ("mine-shell") and high-explosive incendiary. The Minengeschoß was made by drawn steel (the same way brass cartridges are made) instead of being forged and machined as was the usual practice for cannon shells. This resulted in a shell with a thin but strong wall, which hence had a much larger cavity in which to pack a much larger explosive or incendiary charge than was otherwise possible. The incendiary rounds were also often fitted with a hydrostatic fuse, which detonated when it came in contact with liquid. This was to ensure that the round did not merely explode on the target aircraft's skin, which would cause little damage, but instead penetrated and exploded when it came into contact with fuel or coolant inside the fuel tanks or radiators respectively.
ANGELS10 :angel:
-
For muzzle velocity i was going off of this post by lusche:
http://bbs.hitechcreations.com/smf/index.php/topic,280043.0.html
For rounds/sec I was going off of in game test from SunBat.
-
Wow, that's awful velocity. My flintlock rifle does better than that.
That's pretty decent RoF though, 10.8 rounds/second.
-
Then this as a technical simulation seems to be much less concerned about faithfull accuracy at one of the two ends of some wheapons systems since there is no mechanical way to set the elevation above 0-datum motor line with the MK108 or MG151/20 in any motor cannon mounted aircraft Germany produced. At this stage in HiTech's coading genius I doubt he would have any trouble revamping the affected wheapons systems to the manufacturers mounting specifications.
But, again maybe HTC has never had the manuals translated I'm refrencing since there is so much english language translated and post WW2 U.S. government technical data available to coad these systems with. And it seems this audience is vested completely in the results of sticking the pointy stick in the mammoth, in this mammoth hunting simulation, rather than the process behind the pointy stick getting there is a narrow focus worm hole rather than direct arm power.
BFG9000, Chain guns and particule beam sniper rifles anyone?
Bustr, Are you saying that it is known from the links you posted that the back of the cannon could not be shimmed down? Per my calculations it would only take an angle of 1.036 deg on a MK108 to get a 30mm to cross the firing datum at muzzle velocity of 1770 ft/s. If the cannon, from tip of the barrel to the rearmost point, was 10ft long, then the rearmost point would only have to drop 2 inches. That strikes me as a reasonable number, and I can't see anything in the schematics that says that's impossible.
Can you clarify?
-
So you set the gunsight to the fixed position cannon, then you set the adjustable machine guns to the sight position? Do you end up with the same thing we have now?