Would like some 109 training

[boomerlu]

Another test that may be eye-opening on the trajectory "non-issue" is to do this-

Turn on tracers, go into the TA, and engage auto-level.  Use F3 or F5 (I don't remember which one) and zoom way out.  Move your viewpoint to the side of your plane, and fire the guns.  The tracers may/may not follow the exact path of the rest of the bullets, but should be pretty close...  See how flat they shoot?

Good tip - I just tried it (F5 is the right key). This was the kind of test I was going to try originally - might have fallen flat if I hadn't tried using the F5 view.

Doing this, I see the main difference in ballistics isn't so much bullet drop/arc as it is bullet speed. The MK108's bullet speed feels like around half that of the 13mm machine guns. The bullet arc issue once again seems most important for the dead six shot - where the small profile of the target requires higher accuracy. Otherwise, the arc seems like it's at most around 1.5x the height of the plane.

[mtnman]

Good tip - I just tried it (F5 is the right key). This was the kind of test I was going to try originally - might have fallen flat if I hadn't tried using the F5 view.

Doing this, I see the main difference in ballistics isn't so much bullet drop/arc as it is bullet speed. The MK108's bullet speed feels like around half that of the 13mm machine guns. The bullet arc issue once again seems most important for the dead six shot - where the small profile of the target requires higher accuracy. Otherwise, the arc seems like it's at most around 1.5x the height of the plane.

Bullet speed is driving the bullet drop.  Bullet drop is mostly about time.  The quicker it gets to it's target, the less it drops.  If it takes twice as long for the cannon round to get to the target, then it has twice as long to fall, so will fall further (but maybe not exactly twice as far- it'll be close, though).

For example, I can drop one of my .75 cal musket balls, and a .32 cal ball at the same time- they both hit the ground at the same time, too.  But the .75 shoots lower at 100yds.  Why?  Because it flies slower, so has a longer time to fall before hitting the target.  I can also drop one of my 325gr .54 balls at the same time as one of my 400gr .54 conical projectiles.  Both hit the ground at the same time...  But here's the kicker!  The heavier conical flies "flatter" than the lighter ball!  Why?  The ball leaves the muzzle at a higher FPS, but slows quicker, due to drag.  The heavier conical starts out slower, but retains speed better, so actually takes less time to reach the target, therefore has less time to fall!  They both actually fall at about hte same speed- time is the deciding factor.

109 ballistics-  The MG's differ significantly in velocity over the cannons (CR's).  Therefore they take different times to reach a target.  For ease of description, lets say the MG's fly twice as fast as the CR's.  What does that mean on a dead six shot?  Not much, if the convergence is "close enough", because the dead six shot appears almost stationary.  Two rounds, one from the MG and one from the CR, will both hit it.

What about on crossing shots?  Well, here it's a different story!  If an MG and the cannon fire rounds at the same time, it's only possible for one of them to hit the target!  Not both!

Why?  Time again...

If the MG and CR hit the exact same spot, but do it at different times, on a crossing shot, only one of them can hit.  If the aim/lead is correct for the MG, and it hits its target, the CR will be too late!  The target will be gone!  If the aim/lead is correct for the CR, the MG will pass through the air in front of the target, because it's too fast/early...

In reality, the speed on the CR probably isn't 1/2 the speed of the MG, but on a crossing shot on a plane flying 200mph (which is about 300 FPS), a difference of impact time of only 1/4 second is still a difference where the MG hits, and the CR passes 75 feet behind the target...

If you lead correctly for the MG, the CR's are wasted/useless.  If you aim correctly for the CR, the MG's are useless (on crossing shots).

Now, if we add in the effects of banking your plane before you fire, and the fact that even pulling slight G's messes things up royally, and that you're probably firing on an upward or downward slant, is it any wonder the average hit% in AH is so low?

[boomerlu]

Bullet speed is driving the bullet drop.  Bullet drop is mostly about time.  The quicker it gets to it's target, the less it drops.  If it takes twice as long for the cannon round to get to the target, then it has twice as long to fall, so will fall further (but maybe not exactly twice as far- it'll be close, though).

Actually, the bullet drop scales as 1/2 g t^2 if we are going to be technical here.

If you lead correctly for the MG, the CR's are wasted/useless.  If you aim correctly for the CR, the MG's are useless (on crossing shots).

Then is there any point in firing the MG and CRs together on a 109 (besides in a situation where you must absolutely kill the target and don't care about wasting ammo)? If the MGs are to hit, the CR would be wasted. If the CR were to hit, the MG would be wasted. Seems the firing windows for each are entirely different on snapshots.

[mtnman]

Actually, the bullet drop scales as 1/2 g t^2 if we are going to be technical here.

Then is there any point in firing the MG and CRs together on a 109 (besides in a situation where you must absolutely kill the target and don't care about wasting ammo)? If the MGs are to hit, the CR would be wasted. If the CR were to hit, the MG would be wasted. Seems the firing windows for each are entirely different on snapshots.

I'm just a long-haired hippy-type redneck, so try to avoid the formula's, if possible, hehe!  I opted for taking French instead of math in school!

I think you've got the firing window on snapshots idea.  What's the point of firing both?  Maybe to maximize chances of any hit?  Got me...

Of course, there are the differing rates of fire to contend with as well.  Are the CR's and the MG's leaving the barrel at the same time?  (Timed to fire through the prop).   Maybe as the CR hits it's target, an MG round fired at a later time also hits the same target at the same basic time?  We're looking at streams of bullets, rather than at single-fire weapons, after all.

Maybe the aspects of firing while in any but a level position, on a fairly stationary target are too hard to allow for, so they just go with a happy compromise? 

[Madkow]

The only time I fire the MG is when the target is 400 or more out and I need him to turn. People do stupid things when they are under fire. When it's time for a kill shot or deflection shot I only shot the 30mm. 

[boomerlu]

I'm just a long-haired hippy-type redneck, so try to avoid the formula's, if possible, hehe!  I opted for taking French instead of math in school!

Well met sir. I actually went to school with plenty of hippy-rednecks who were good at math . You probably won't meet a stranger combination of characteristics than me though - Asian Physicist/Rockstar (got a ring in each ear) with a touch of country from growing up in TX. My parents said "son, you gotta learn an instrument" so I said "HEY! How about electric guitar?" 

I joke with the AH folks that I turned to physics after I found out I couldn't fly jets because I'm nearsighted (funny thing - I don't fly AH unless I have my contacts on).

Anyways, on to business...

Maybe as the CR hits it's target, an MG round fired at a later time also hits the same target at the same basic time?  We're looking at streams of bullets, rather than at single-fire weapons, after all.

True, but after thinking about it - I'd rather fire just one or the other (CR only or MG only) on those snapshots. MG bursts tend to be longer than MK108 bursts, so there's a lot of waste there.

I'm agreeing with Madkow here - MG for dead six chase shots to get him to turn (or if you get lucky the MG can do critical damage) and CR for the kill shot.

Still, as we're talking about 109s here, there isn't any reason NOT to set the convergences to the same value (between MG and CR). The MG has good enough ballistics that it's no hassle to manually adjust on those longer shots. And in case you actually DO want to fire the two guns together, you'll have everything set up to converge properly.

[mtnman]

I think your right, there's probably no real need/benefit to set the guns for differing convergences. 

But, I can speculate that setting the CR for a much further convergence may actually be beneficial.  This would appear to be a way to increase the lead of the cannons over the MG's mechanically, for a banking snapshot.  If this would work, I'd set my MG's for about 275, and the cannons for 650(?).  From what I've seen with the .target testing, this still wouldn't result in the CR's going over closer targets.  I could be wrong.

As far as practical experience, I have none to speak of with planes that use both MG and CR.  All of the planes I fly regularly have 6x .50's.  One of them has 4x20mm.  Given the choice, I like the 6x .50 package best, because I like the high rate of fire.

[boomerlu]

But, I can speculate that setting the CR for a much further convergence may actually be beneficial.  This would appear to be a way to increase the lead of the cannons over the MG's mechanically, for a banking snapshot.  If this would work, I'd set my MG's for about 275, and the cannons for 650(?).  From what I've seen with the .target testing, this still wouldn't result in the CR's going over closer targets.  I could be wrong.

I've played with this idea in my head. If the gun fires higher, then I get more lead! However, with the style I fly and the guns solutions I typically get, I predetermine lead before I fire the shot so this wouldn't be that much of an advantage. This would probably be better for turn-fighters who could use that extra few angles.

As far as practical experience, I have none to speak of with planes that use both MG and CR.  All of the planes I fly regularly have 6x .50's.  One of them has 4x20mm.  Given the choice, I like the 6x .50 package best, because I like the high rate of fire.

Dedicated to American birds I see? I tend not to find too much ballistics difference between 20mm and MGs, the big difference and hassle comes with the 30mm. Again with everything we've discussed so far, it appears that it's not really best to fire 30mm and MG together anyways so we don't have to deal with competing ballistics. Rather we just have two different set of ballistics, each for a different role.

[mtnman]

I agree!

American birds?  Yup, but actually I don't really have any interest in any of the the planes in AH other than the F4U, the B17, and the B25.  I find the rest to be too goofy-lookin' to interest me, although the P51 isn't terrible.

[boomerlu]

Just observing: I've only seen the 6x50 cal package on American planes and going off that I guessed that the 4x20mm was the C Hog. To each his own. I've tried out a lot of the planes in AH, but I keep coming back to the 109s.

[Madkow]

See if this helps at all Boomerlu.. Its about 10 or so kills. You can see how I only fire the MG to get them to turn and then kill them with the 30mm..
http://www.mediafire.com/file/zzmjyzmwjkz/K4.ahf
 

[boomerlu]

See if this helps at all Boomerlu.. Its about 10 or so kills. You can see how I only fire the MG to get them to turn and then kill them with the 30mm..
http://www.mediafire.com/file/zzmjyzmwjkz/K4.ahf

I get the first few kills, then AHFV crashes afterwards . Oh well, I get your point, I'm starting to use my guns in a similar fashion now. Taters are starting to land .