What happens with Mk108?

[Horten]

Hi all. I have a question.

The Mk108 cannon (30mm) had in real life a maximum rate of fire of 650 rounds per minute. One minute have 60 seconds, now the maximum rate of fire is 10,83 rounds per second (650/60). Why in the game the fire rate of Mk108 is a lot slower?

This cannon is mounted in Bf-109 K4/G14, Me-262, Me-163, Bf-110, Fw-190 and Ta-152.

[Lusche]

Originally posted by Horten
Hi all. I have a question.

The Mk108 cannon (30mm) had in real life a maximum rate of fire of 650 rounds per minute. One minute have 60 seconds, now the maximum rate of fire is 10,83 rounds per second (650/60). Why in the game the fire rate of Mk108 is a lot slower?

This cannon is mounted in Bf-109 K4/G14, Me-262, Me-163, Bf-110, Fw-190 and Ta-152.

I canīt duplicate this.

I just did a few tests in a 109K4. I was able to empty the 108 magazine in about 6 seconds each time. As the magazine holds 65 rounds, you get a ROF of ~11.
Testing the Ta152, I got similar results.

The ROF in game seems to be correct.

[Zwerg]

Maybe Horten is fooled by the sound. Looks like you get a boom every 2nd round.

[EagleDNY]

I did a lot of Cannon ROF testing - the Mk 108 tested out at a little over 10 rnds / second (ROF 600), which is at the low end of the rating for this cannon, but within the spec of 600-650 quoted by many sources.

Last testing thread I did is here:
http://www.hitechcreations.com/forums/showthread.php?s=&threadid=166056

EagleDNY
$.02

[Treize69]

Agreed, seems pretty spot on to me. Dont go by the sound, watch the counter. Counts down FAST.

[Horten]

Yes, the cannon fire a lot of bullets, but you only can see few of them. Now, what happens? You can shoot down an enemy by an invisible bullet?

[Apeking]

In a way you're correct - you shoot down the enemy with invisible shells. When you pull the trigger the game engine generates a graphical effect that represents tracer bullets, which form a minority of rounds in each ammunition belt. As far as I can tell the game doesn't model little bullet polygons in flight, or at least it would be a waste of processing power to do so.

Nonetheless the game tracks each bullet, at least as far as 1.5k from your position, rather than the situation in previous games whereby the game engine would track an abstract damage value blob that travelled from your aircraft to the enemy's hit bubble.

[Reynolds]

Originally posted by Horten
Yes, the cannon fire a lot of bullets, but you only can see few of them. Now, what happens? You can shoot down an enemy by an invisible bullet?

The shots you are looking for, the ones you can see are called 'Tracers'. They are heavier (I beleive) than your average bullet, and give off light allowing you to see them. The bullets you dont see arent invisible, they are normal rounds. On average, in modern days, every fifth bullet is a tracer. That means for each bullet you see, there are four more in between you CANT see. Assuming the ratio of tracer:normal is 1:5, then in that 65 rounds you will only see 13 shots. Again, dont trust sound, dont trust sight. Hell, dont trust anything. Fly high, shoot straight, and DEFINATELY conserve ammo! One thing I do, and I would definately suggest you do as well, fire one shot at a time. Tap the trigger once, and just tap multiple times for more shots. That way you can count for yourself how many shots you fire, and you wont run out without some warning.

[Krusty]

I don't think tracers are any heavier. They are standard rounds that are dipped/coated in a substance that glows with the heat of the ignition of the gunpowder, basically. The explosive content of the shell is still about the same as the the non-glowing ones

[Reynolds]

Originally posted by Krusty
I don't think tracers are any heavier. They are standard rounds that are dipped/coated in a substance that glows with the heat of the ignition of the gunpowder, basically. The explosive content of the shell is still about the same as the the non-glowing ones

It is VERY slightly heavier, so that at long distances, it drops faster. I have always been told, by every active duty member I have spoken to on the subject, never aim EXACTLY with the tracers. Your shots are going higher than the tracers, and you learn to compensate. Its nothins at close range, but at 1000 yards its a notable difference. Or so I have been told. Logically as well, any coting/flare will add a little weight. Not much, but enough to make a difference at range.

[zorstorer]

Originally posted by Reynolds
It is VERY slightly heavier, so that at long distances, it drops faster. I have always been told, by every active duty member I have spoken to on the subject, never aim EXACTLY with the tracers. Your shots are going higher than the tracers, and you learn to compensate. Its nothins at close range, but at 1000 yards its a notable difference. Or so I have been told. Logically as well, any coting/flare will add a little weight. Not much, but enough to make a difference at range.

Actually they should be a bit lighter if anything.  They are not coated with anything.  If it is standard ball ammo then there is a cavity hollowed out in the rear of the bullet and the tracer substance is filled into the cavity.  So unless the periodic chart is crazy and any of the commonly used tracer materials are somehow heavier than lead/steel then the weight of a tracer round should be slightly less than a standard ball round.  Plus as the tracer burns the weight of the bullet actually goes DOWN during flight.  Also the burning of the tracer substance can cut down on the parasitic drag produced as the air flows back around the rear of the bullet.  Almost like a "base-bleed" artillery round.

Here is more on base bleed technology....

Here

So if anything you need to aim a bit lower than what your tracer rounds tell you as your tracers are hitting high.

[Reynolds]

Originally posted by zorstorer
Actually they should be a bit lighter if anything.  They are not coated with anything.  If it is standard ball ammo then there is a cavity hollowed out in the rear of the bullet and the tracer substance is filled into the cavity.  So unless the periodic chart is crazy and any of the commonly used tracer materials are somehow heavier than lead/steel then the weight of a tracer round should be slightly less than a standard ball round.  Plus as the tracer burns the weight of the bullet actually goes DOWN during flight.  Also the burning of the tracer substance can cut down on the parasitic drag produced as the air flows back around the rear of the bullet.  Almost like a "base-bleed" artillery round.

Here is more on base bleed technology....

Here

So if anything you need to aim a bit lower than what your tracer rounds tell you as your tracers are hitting high.

Thanks, I knew there was a difference in weight, I just couldnt quite remember if it was lighter or heavier. I just thought real hard and guessed heavier

[Krusty]

Zorstorer: That only applies to solid rounds, perhaps just MGs. We're talking cannon rounds. Cannon tracers are no less explosive, they're just coated.

Reynolds, maybe the folks were telling you about MG rounds going downhill. Maybe they were talking about 50cals on GV mounts or something. I'm fairly sure no Mk108 30mm is going to be spotted or aimed 1000 yards out >:D

The trajectory is too poor to even HOPE for that kind of range.

[Reynolds]

Originally posted by Krusty
Zorstorer: That only applies to solid rounds, perhaps just MGs. We're talking cannon rounds. Cannon tracers are no less explosive, they're just coated.

Reynolds, maybe the folks were telling you about MG rounds going downhill. Maybe they were talking about 50cals on GV mounts or something. I'm fairly sure no Mk108 30mm is going to be spotted or aimed 1000 yards out >

The trajectory is too poor to even HOPE for that kind of range.

They were talking about MGs aimed UP at aircraft. I dont know **** about cannon, but I thought I would use MG tracers to explain why he can only see a few shots. But yeah, tracers are lighter, so you have to aim below. and hey, we fire .50s from 1000 out all the time on B-17Gs and score kills. As long as you can compensate for the trjectory 1000 yards isnt THAT far...

[Krusty]

You only get kills that way because you're moving 300mph in the opposite direction. Thus the plane running into them at 310mph following your is closing the distance. Your bullets are only traveling about 600-800 yards before they hit the aircraft, but the moment you fire it you keep moving on, and the enemy plane moves in, so you get hits at further distance. The rounds themselves really aren't reliable at those ranges.

Consider the 50cals when you're in one fighter chasing another. Even if the other guy flies straight, at 1k your chances of hitting him (other than 1 random hit sprite) are almost zero.