I’m just gonna disprove this real quick with the German penetration data for the MG 131 firing a ligther round at less velocity:
You see that the weaker 13mm AP round penetrates 19mm at 100m and still 7mm at 500m, while carrying much lower KE at any range than US .50cal AP rounds, which are also more aerodynamic.
Do we have accurate data for muzzle velocity etc.? I know how “reliable” German handbooks are.
96g would make it a bit more ballistically superior, I guess. But I would also expect lower MV, and unlike Germans who tested multiple configurations for MG151/20, for Soviet shells it seems like we have some “handbook” or “openly published” numbers, that can as well be unreliable.
Anyway, Shvak is horribly overperforming ballistics-wise and even tracer base bleed effect is not enough to explain this.
If the damage at least scaled down with the distance. But nuh uh.
And on .50 cal ballistics - yeah,. it’s a boattailed relatively heavy bullet, it has all the reasons to keep going at high speed.
BTW Breda should have a lot better ballistics than Mg131 due to better bullet design. Hope it’s reflected in game.
I wonder why did Germans go with the most braindead design for their ammo, while standard kar98k bullet was designed with excellent long range ballistics for its caliber. It’s like they did not care about distance longer than 400m.
Bring a SOURCE. Stop arguing with your feelings.
Well, the MG 131 boost some pretty good firepower for the weight at the cost of range.
But for most pilots, they wouldn’t be able to make use of longer ranges anyway and the closer you get the higher the chance of hitting the target.
I have two Russian documents. One snipet showing some ballistic data for aircraft guns and the T-60s firing table.
But it just shows the time for the shell to reach certain distances.
Compared to the MG 151 Mineshells it does so quicker.
Of course we don’t know the ammo type for the ShVAK, only that it’s supposed to be 815m/s:
Compared to a pretty fast 20mm Mineshell:
The Mineshell slows down much quicker.
The T-60 firing table only has a single decimal place. So the firing times are less accurate but it says 2.3s for 1000m for rounds fired at 800m/s.
Well, not that much.
800m in 1,59 vs 800m in 1,95 for mineshell.
1000m in 2,8 vs 2,21. Yes, Shvak is going stronger. But not that much stronger it seems. The initial speed bleed is substantial and I don’t think a 900+m shot in a tailchase should be viable.
Although Shvak seems to barely slow down past 800m. Which is pretty interesting. I mean, between 800 and 900 and 900 and 1000 it’s almost the same flight time, which is extremely weird.
It probably means Shvak has a lot better transsonic and subsonic ballistics than M-geschoss, while at supersonic it’s doing actually a not-so great job!
But it’s awesome, I’ll type this into excel and get exact speeds + the speed bleed at 955m/s compared to 815m/s!
And regarding MG131 - all I’m saying is that with Breda’s bullets it would have longer effective range and shorter flight time. MG131 had very stable, well designed and devastating AP - punching full caliber hole while virtually ignoring aircraft skin. It was well designed from terminal ballistics point of view. But the shape, lack of boat tail… well, I guess they wanted the MG to kinda mirror the MG151/20, so better ballistics were actually counter-productive.
in the game US 50 cals have 20mm flat pen at 500m.
so… nerf US 50cals?
This guy just made up data.
Meanwhile, I have a US Army manual!
8 inch groups at 500 yards is extremely solid for any HMG, even in modern times. There’s a reason why skilled Sabre pilots in Korea were able to land shots on MiG’s at up to a kilometer once the radar gunsight got a lock.
But I think that’s data for the M2HB with a 45" barrel compared to the aircrafts 36".
It’s longer and heavier, probably resulting in less vibriation.
I also wondered how they made that 2km shot in Vietnam but I guess the aircraft AN/M2 is just not really built for accuracy.
Of course one must also considerer the circumstances. A long burst from an aircraft gun, firing with a high RoF, is going to heat up the barrel, particular when it’s a lighter barrel, resulting in much greater dispersion comapred to controlled short bursts from a ground MG.
Here’s the Berezin in comparison:
With the AN/M2 firing the round at 865m/s, the ballistics are probably very similar.
But that’s a big difference.
I generally consider 0.5s and lower the optimal time for a high chance to hit and 1s the maximum of being able to make reliable hits.
Of course when the target is flying straight, you can also hit at ranges that lie outside 1s travel time.
For the MG 151/20 (and MG 131), 300m and lower is ideal while at 500m and more it’s getting increasingly difficult to land hits with Mineshells or 13mm rounds.
The 12.7mm has an easy time hitting at 400m but can also hit up to 700m.
Bullet drop also plays a role, which makes it rather difficult for the MG 151/20 and MG 131 to land shots past 500m, since they slowed down so much that they just keep droping more and more.
That’s not as big of a difference as I though, that’s all.
Still it’s significant.
But interesting stuff happens once it hits transsonic. It’s clear that M-geschoss has horrible transsonic ballistic coefficient. At supersonic there’s not THAT big of a difference.
Which leads me to believe M-geschoss may lose stability once its speed drops under mach 1, and then it simply starts to wobble and bleeds even more speed.
| ShVAK 815m/s | MG 151/20 790m/s | ||||||
|---|---|---|---|---|---|---|---|
| Range | Time | Delta Time | Range | Time | Delta Time | Velocity | |
| 100m | 0.13 | 0.13 | 100m | 0.136 | 0.136 | 685m/s | |
| 200m | 0.27 | 0.14 | 200m | 0.294 | 0.158 | ||
| 300m | 0.43 | 0.16 | 300m | 0.479 | 0.185 | ||
| 400m | 0.61 | 0.18 | 400m | 0.696 | 0.217 | ||
| 500m | 0.82 | 0.21 | 500m | 0.952 | 0.256 | 363m/s | |
| 600m | 1.05 | 0.23 | 600m | 1.249 | 0.297 | 314m/s | |
| 700m | 1.31 | 0.26 | 700m | 1.588 | 0.339 | ||
| 800m | 1.59 | 0.28 | 800m | 1.965 | 0.377 | ||
| 900m | 1.89 | 0.30 | 900m | 2.371 | 0.406 | ||
| 1000m | 2.21 | 0.32 | 1000m | 2.792 | 0.421 | 234m/s | |
| 1100m | 2.55 | 0.34 | |||||
| 1200m | 2.91 | 0.36 |
Speed of sound is 343m/s at sea level.
| MG 151/20 790m/s | MG FF/M 695m/s | |||||||
|---|---|---|---|---|---|---|---|---|
| Range | Time | Delta Time | Velocity | Range | Time | Delta Time | Velocity | |
| 100m | 0.136 | 0.136 | 685m/s | 100m | 0.155 | 0.136 | 597m/s | |
| 200m | 0.294 | 0.158 | 200m | 0.337 | 0.182 | |||
| 300m | 0.479 | 0.185 | 300m | 0.551 | 0.214 | |||
| 400m | 0.696 | 0.217 | 400m | 0.801 | 0.250 | 370m/s | ||
| 500m | 0.952 | 0.256 | 363m/s | 500m | 1.093 | 0.292 | 319m/s | |
| 600m | 1.249 | 0.297 | 314m/s | 600m | 1.428 | 0.335 | ||
| 700m | 1.588 | 0.339 | 700m | 1.801 | 0.373 | |||
| 800m | 1.965 | 0.377 | 800m | 2.203 | 0.402 | |||
| 900m | 2.371 | 0.406 | 900m | 2.632 | 0.429 | |||
| 1000m | 2.792 | 0.421 | 234m/s | 1000m | 3.052 | 0.420 | 231m/s |
Niiice, thank you very much.
Wonder what kind of shell is that.
Anyway, I’m kind of surprised by the 815m/s speed. Especially when MG151/20 was able to achieve 720m/s with 117g shell, I kind of assumed the theoretical capabilites od MG151/20 were very similar (probably because I looked at 90g and 800m/s muzzle velocity, both too low compared to real Shvak ammo - it’s also velocity vs momentum kind of problem).
But now I understand Shvak was higher powered weapon. Not by much, but coupled with superior ballistics, it made a noticeable difference, in WT this should translate into effective range higher by about 20%, and wirh a ton better ability for super long range shots.
The muzzle velocity of the ShVAK remains a bit of a mystery.
In general both produce roughly the same muzzle energy.
If we consider the 96.5g API being fired at 800m/s compared to the MG 151/20 El. firing a 117g AP round at 720m/s.
ShVAK used 18g of propellant powder, MG 151/20 around 18.5-19.5g but the MG 151/20 has a much shorter barrel with 1100mm compared to the ShVAK with either 1250mm or 1540mm.
| ShVAK 815m/s | MG 151/20 IT 720m/s | ||||||
|---|---|---|---|---|---|---|---|
| Range | Time | Delta Time | Range | Time | Delta Time | Velocity | |
| 100m | 0.13 | 0.13 | 100m | 0.145 | 0.145 | 660m/s | |
| 200m | 0.27 | 0.14 | 200m | 0.303 | 0.158 | ||
| 300m | 0.43 | 0.16 | 300m | 0.477 | 0.174 | ||
| 400m | 0.61 | 0.18 | 400m | 0.666 | 0.189 | ||
| 500m | 0.82 | 0.21 | 500m | 0.874 | 0.208 | ||
| 600m | 1.05 | 0.23 | 600m | 1.101 | 0.227 | ||
| 700m | 1.31 | 0.26 | 700m | 1.348 | 0.247 | ||
| 800m | 1.59 | 0.28 | 800m | 1.616 | 0.268 | ||
| 900m | 1.89 | 0.30 | 900m | 1.905 | 0.289 | 334m/s | |
| 1000m | 2.21 | 0.32 | 1000m | 2.215 | 0.310 | 312m/s | |
| 1100m | 2.55 | 0.34 | 1100m | 2.545 | 0.330 | ||
| 1200m | 2.91 | 0.36 | 1200m | 2.895 | 0.350 | 279m/s |
Let’s have a look at the FI-T and IT rounds. Their weight and tracer should make them aerodynamically superior compared to the lighter ShVAK ammo.
And in fact, despite the round being much slower at first, it reaches 1200m at around the same time.
A shorter barrel is actually going to mean less vibration than a longer one, and with less barrel droop when it gets hot. There’s a few marksman rifles on the US market designed around that with relatively thick but short barrels designed to maintain accuracy even under repeated firing. As long as you can get up to the necessary velocity having a longer barrel just impedes accuracy instead of enhancing it since a longer barrel is harder to keep in tolerance as well as having greater potential for uneven heating. And for the distances we’re talking about the velocity loss won’t really matter all that much, especially since we’ve already seen firing charts posted up of how accurate the guns really were when wing-mounted, and they were no worse than any land-based mount.
As to the heating issues, not at all since the fast-moving air cooled it down far better than the passive dissipation on a land vehicle or crew-served mount, no different from sticking a fan on a CPU’s heatsink. Because of that extra cooling you’d actually be less likely to overheat. The “HB” in M2HB stands for “heavy barrel”, since unless you were flying around at a few hundred MPH you needed either a heavy thick barrel or a water jacket to act as a heat sink, and the water jacket with a light barrel added 40 pounds of dead weight compared to the HB version.
You should check the chamber pressures just to be sure. The US M1 76mm cannon had identical performance to the 3-inch M5 even with the shorter barrel since we used a smaller cartridge with no wadding at the top to jack up the chamber pressure and get that round moving down the barrel a lot faster.
EDIT: Here’s a USAAF .50 cal chart for the .50BMG in the P-38.
At 3,000 feet/914m, a 12 foot circle is still enough to land hits on a plane that’s minimal profile (a Fw 190 A-8 has a wingspan almost triple that and a tail just under that). At 750 feet/228m 75% of your rounds if fired directly at the fuselage from behind in a straight line will go right through and hit the engine. When you combine any obliquity and the fact you’ve got four guns firing, its accurate enough.
No, there already vehicles that can easily be destroyed by MGs and its annoying.
It says 16" groups at 500 yards while the other clearly shows a greater dispersion at just 400yrds.
With a 4 mil dispersion cone at 400yrds we’re already at 4.8feet
You do realize that the guns are stuck inside a wing or nose mount?
Just becaus they are cooled via airflow, doesn’t mean they not going to heat up rapdily in a short time, just before they cool down after a short time.
At that range, you are not going to make any deflection shots against fighters.
Even under ideal circumstances it would look like this:
And you have to remember that only 3/4 of the bullets are even hitting that area and even less are going to hit critical components.
And that is in addition of having the perfect aim to even make it possible.
So if we imagine a tail-chase. You need to aim perfectly at the fuselage, adjusting for range, then out of the 3/4 of bullets in that circle, only a 1/3 or 1/4 is going to hit.
Meaning only 20% of the rounds fired even have a chance to hit the plane.
And that’s only realistic with WT mouse aim, where the plane is actually staying perfectly on target.
You act like there’s empty space though and not a bunch of stuff inside. Will it snap the wings? No. Will it blow the plane up in a fiery ball of glory—depending on the circumstance—but no. Having all the insides of your plane shredded makes it difficult to maneuver as hydraulic lines, electrical lines, pilot controls, the oxygen which by the way, would be very dangerous if hit and it springs a leak. All that stuff matters, and that’s not counting the spalling that would occur from striking anything structural within the aircraft
Like how Gaijin added more modules to tanks, I think more elaborate and detailed modules would be useful and reducing cannon damage and fixing damage models would make the game a lot more fun as glancing blows could be dangerous. More so than the I-clicked-my-mouse-once-and-I-blew-you-up. Meta we have.
