109 vs Spitfire

[Karnak]

The single Hispano still hits harder than a single MG151/20, or so it seems.

It does by a fair margin if building damage values mean anything.

The only 20mm cannon close to the Hispano on damage per hit is the Type 99 Model II carried by the N1K2-J and A6M5b, but that cannon has a much lower rate of fire and lower muzzle velocity.

[GScholz]

How much damage does each gun do against buildings then?

The Hispano II needs to be at least 20% more powerful per round to make up for the MG151/20's higher ROF. For every 10 Hisso rounds the MG spits out 12.

[Karnak]

I am at work and don't have the exact numbers, but I recall something like 3.4lbs for the MG151/20 and 4.1lbs for the Hispano Mk II.

Also, shooting airplanes isn't the same as shooting buildings.  You can't simply says "x damage per second" as you are very unlikely to get solid hits for that long.

[GScholz]

20mm Hispano Mk II   4.03
20mm MG 151/20    3.55

So while the Hispano II does 13.5% more damage per round the MG 151/20 actually does more damage per burst.

Hisso one second burst (10 rounds): 40.3 lb

Mg 151 one second burst (12 rounds): 42.6 lb

[Karnak]

20mm Hispano Mk II   4.03
20mm MG 151/20    3.55

So while the Hispano II does 13.5% more damage per round the MG 151/20 actually does more damage per burst.

Hisso one second burst (10 rounds): 40.3 lb

Mg 151 one second burst (12 rounds): 42.6 lb

Factor in that the Hispano's damage is more concentrated and that unless you're shooting bombers you're unlikely to get a full 1 second burst with all rounds hitting.  Also ballistics due to muzzle velocity.

[GScholz]

Half second burst Hisso/MG: 20.15 (5 rnd) / 21.3 (6 rnd)

Quarter second burst Hisso/MG: 8.06 (2 rnd) / 10.65 (3 rnd)

1/6 second burst Hisso/MG: 4.03 (1 rnd) / 7.1 (2 rnd)

With less than 1/6 second both guns only get off one round, and then the Hispano II does 13.5% more damage.

[Karnak]

Not worried about that so much as individual hits and damage concentration.

The Bf109G-2 or Spitfire Mk IX get a crossing shot on the other they are likely to only hit with one round, maybe two for the Spitfire due to two cannons.

[GScholz]

Not in my experience, but YMMV I guess. You're right in that the Spit with two cannons has a much better snapshot than the 109, but that's not what I was arguing.

[BaldEagl]

How much damage does each gun do against buildings then?

The Hispano II needs to be at least 20% more powerful per round to make up for the MG151/20's higher ROF. For every 10 Hisso rounds the MG spits out 12.

Who's flying either one against buildings?  Air to air I'd put my money on the Hispano's ballistics regardless of "damage per burst".

[Charge]

Damage, what damage? And against what? AP or HE? It makes a big difference depending on the range. Hisso retains its kinetic i.e. AP damage better on long range but the chemical energy of 151/20 stays nearly constant with range.

IRL the difference in ballistics was not as marked as in AH so I'd choose 151/20 with MG ammo over Hisso if I'd be to shoot down other planes. But I agree that in this case two Hispanos are better than one 151/20.

And do not make a mistake thinking that a long barrel makes a gun more accurate or reduces dispersion as it is likely to work the other way in rapid fire aircraft application. Longer barrel makes it possible to use slower powder as a driver which is better for the breech but in turn it needs a longer barrel to burn it all effectively to give a good muzzle velocity.

-C+

[Noir]

IRL the difference in ballistics was not as marked

I'd love to see proof of that.

[Karnak]

Damage, what damage? And against what? AP or HE? It makes a big difference depending on the range. Hisso retains its kinetic i.e. AP damage better on long range but the chemical energy of 151/20 stays nearly constant with range.

IRL the difference in ballistics was not as marked as in AH so I'd choose 151/20 with MG ammo over Hisso if I'd be to shoot down other planes. But I agree that in this case two Hispanos are better than one 151/20.

And do not make a mistake thinking that a long barrel makes a gun more accurate or reduces dispersion as it is likely to work the other way in rapid fire aircraft application. Longer barrel makes it possible to use slower powder as a driver which is better for the breech but in turn it needs a longer barrel to burn it all effectively to give a good muzzle velocity.

-C+

The difference is accurate here, yet I would still choose the MG151.20 over the Hispano in RL.  Put MG151/20s in place of the Hispanos on the Spitfire and you get a more maneuverable Spitfire with more firing time.  The Hispano's greater ability for long range shots is insignificant in comparison.  Such shots were extremely rare and hard to make.

[Wmaker]

Tony Williams mentions Hispano MK.II's rate if fire as 600rpm. In AH, it's 650rpm per my testing.

http://www.quarry.nildram.co.uk/WW2guneffect.htm

Wikipedia talks about 600-700rpm.

[GScholz]

Unless it has been changed the Hisso has a cyclic rate of 600 rpm. Pyro stated this on the bbs several years ago.

[Wmaker]

I timed using multiplier 6 for the ammo. It takes a hispano ~66.3 secs in game to spit out 720 rounds. That's 651.58 rounds per minute and considering my reaction time and using a cell phone timer I'm quite sure it is set to 650rpm.