Hit rate- cannons vs mg

[SunTracker]

Now isnt it true that it was easier to land more critical hits on another aircraft with machine guns than it was cannons?

[HoHun]

Hi Suntracker,

>Now isnt it true that it was easier to land more critical hits on another aircraft with machine guns than it was cannons?

Definitely not.

Regards,

Henning (HoHun)

[Kweassa]

No. It was easier to just land hits with machine guns than cannons.

 When the adjective 'critical' comes into the picture, no machine gun round hit will ever be as 'critical' as a cannon round hit... (unless a shot goes through the pilot's head or something).

[SunTracker]

I believe on average it took 20-30 rounds of fifty caliber to bring down an enemy fighter.

It took about 3 rounds of 20mm to bring down a fighter I believe.

I think it would be easier to land 20 to 30 hits of 50 cal.

[HoHun]

Hi Suntracker,

>I think it would be easier to land 20 to 30 hits of 50 cal.

Well, a numerical comparison is only meaningful if you define a basis for the comparison.

For example, you could say you'd allocate 1000 lbs to the armament of a fighter and see what kind of firepower that would give you. (That's about the weight of the P-47's battery.)

Here's what would result from formulating such a requirement to an aircraft designer if you'd also specify using an equally destructive ammunition load for each battery:

6x MK 108 - 14 rpg - 411 kg - 30,2 MW firepower - firepower per weight: 73,5 kW/kg - 60 shells/second
2x MK 103 - 37 rpg - 351 kg - 8,2 MW firepower - firepower per weight: 23,3 kW/kg - 14 shells/second
8x MG 151/20 (MX) - 47 rpg - 416 kg - 11,2 MW firepower - firepower per weight: 27 kW/kg - 96 shells/second
8x MG 151/20 - 52 rpg - 424 kg - 10,1 MW firepower - firepower per weight: 23,9 kW/kg - 96 shells/second
8x Hispano V - 53 rpg - 440 kg - 9,9 MW firepower - firepower per weight: 22,4 kW/kg - 96 shells/second
7x Hispano II - 59 rpg - 451 kg - 7,4 MW firepower - firepower per weight: 16,5 kW/kg - 70 shells/second
10x MG-FF - 45 rpg - 432 kg - 7,8 MW firepower - firepower per weight: 18,1 kW/kg - 80 shells/second
5x MG 151 - 239 rpg - 427 kg - 2,2 MW firepower - firepower per weight: 5,1 kW/kg - 60 shells/second
12x MG 131 - 259 rpg - 447 kg - 2,5 MW firepower - firepower per weight: 5,7 kW/kg - 180 shells/second
8x ,50 Browning M2 - 250 rpg - 452 kg - 2,3 MW firepower - firepower per weight: 5 kW/kg - 104 shells/second
15x Browning ,303 - 665 rpg - 449 kg - 1,3 MW firepower - firepower per weight: 2,9 kW/kg - 300 shells/second

(Edited to fix rpg figure)

For evaluating the results, just compare each battery suggestion to any other.

For example, you could compare the Browning M2 battery to the MG151/20 battery: Both use 8 barrels and put out about the same number of projectiles, but the MG151/20 is about 4.4 times more destructive.

Though in that example, each cannon is a bit heavier than each MG, the higher destructiveness of cannon shells means that the ammo load is a bit lighter, making up for the difference in weapon weight.

For an equal battery weight, the machine guns don't even have an advantage over the cannon in bare projectile count, so there's not much reason to assume you'd have any hit ratio advantage with MGs (at least not with the Browning M2).

If you think the Browning M2's trajectory gives it a hit rate advantage (usually, the literature tends to overestimate the effect since fighter combat was decided at rather short range in WW2), you can swap the MG151/20 for the Hispano II, which still has about 3 times the firepower of the Browning M2 with a similarly flat trajectory.

Projectile count for the Hispano II goes down slightly, but since each projectile is vastly more destructive with cannon, the Hispano in the end wins in this comparison just as easily as the MG151/20.

If you decide to use real-life batteries for comparison, you'll find that the machine-gun armed aircraft usually carry a lot more weight in terms of armament and ammunition to achieve similar firepower as cannon-armed aircraft, so the superiority of cannon is somewhat hidden. Still, every MG-equipped WW2 fighter would have benefitted from a firepower increase if it would have been switching to cannon.

Regards,

Henning (HoHun)

[GScholz]

What's that last MG151 entry in your list? and why only 5?

[SonHiro]

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New Sentence.This is kind of a silly question. Period.

New sentence. Cannons will have more critical hits than MG per round simply because cannons fire stronger rounds. Period.

Space

New Sentence. However, it would be easier to hit with MGs than cannons due to all sorts of factors such as recoil and bullet tragectory. Period.

End Typing

[SonHiro]

For example, take a very destructive MG such as the .50 Cal firing API bullets. it took anywhere from 15-30 rounds to kill a plane (Not counting head shots, or freak engine/fuel tank 1 hit kills which were rare)

Then, look at the 262A-2(i think. it was one of em) with the Big Bertha tater cannon on the nose. 1 shot kills. provided you hit.

[HoHun]

Hi Gscholz,

>What's that last MG151 entry in your list?

That's the original 15 mm MG151.

>and why only 5?

Having allocated 1000 lbs to the battery, I first subtract the weight of the ammunition required for a certain muzzle energy from it. The remaining weight is used to fit as many weapons as possible into the battery.

Since 15 mm projectiles are heavier for the same energy than 20 mm shells and the 15 mm MG151 is as heavy as a 20 mm MG151/20, that leaves the 15 mm with fewer barrels.

Note that the MG151 15 mm battery has virtually the same firepower per weight ratio as the 12.7 mm Browning M2 battery, which might be the reason the US gave up their plan on copying the MG151 as 0.60" HMG. No significant advantage!

(I could have used 6x MG151, but then I'd have overrun the 1000 lbs limit. The 5x MG151 battery is a hair weaker than the M2 battery, but a hair lighter as well.)

Regards,

Henning (HoHun)

[SunTracker]

No fighter mounted 8 cannons in World War II though.  Highest I know of is 4 cannons.

A post war report showed the 50 cals could have been much more effective.  There were three ways in which 50 caliber ammunition usually destroyed enemy aircraft.  (1) Exploding the ammo stores (2) igniting fuel tanks (3) killing the pilot.  It was found that the only truely effective 50 caliber ammunition was armor piercing incendiary.

[Schaden]

I've used the D9 mostly for the last two tours with some 300 odd kills - went back to the P51 for a couple of flights and suddenly realised how weak the P51 guns seemed in comparison - just couldn't get the snap shot kills that you get with the D9.

Is there any doc showing what the effectiveness of the guns of the various planes are in the game? I have seen a number showing effectiveness of the real life gun packs but is there any way of checking how this data carries over to AH?

[HoHun]

Hi Suntracker,

>No fighter mounted 8 cannons in World War II though.  Highest I know of is 4 cannons.

That's because 4 cannons offered the best compromise between firepower and performance. To get halfway decent firepower, you had to use many more MGs than cannon, that's why you see 8 gun fighters.

I'm sure the P-47 could have mounted 4 x 20 mm cannon in each wing if it had been demanded by the USAAF. Supermarine made plans to mount 3 x 20 mm in each wing of the Spitfire, and the Jug is a lot bigger than the Spit.

>A post war report showed the 50 cals could have been much more effective.  

Late-war cannon ammunition could have been much more effective as well. The Luftwaffe was developing special fuel-tank buster shells, for example, that were even more lethal against bombers than the highly effective shells they already had.

Post-war, it became that the best cannon developed in WW2 was the 30 mm MG213C revolver cannon. It was copied by the British and the French and continously developed as the Aden respectively DEFA cannon. The DEFA was selected for the Dassault Rafale, a latest-generation jet fighter, for example.

>It was found that the only truely effective 50 caliber ammunition was armor piercing incendiary.

My calculations are for a pure API loadout for the Browning M2.

Regards,

Henning (HoHun)

[Karnak]

Ah yes, the myth of the Browning .50 caliber machinegun's superiority rears it's head again.

It is a myth though.  The VVS, Luftwaffe, RAF, IJN and IJA did not all stupidly decide that 20mm cannons were the optimum fighter gun at the time.  Heck, the IJA liked the Browning .50 so much they copied it, lightened it for the Ho-103 12.7mm and upscaled the lightened version for Ho-5 20mm.  You'll notice that is what the Ki-61-I-Tei, Ki-61-II, Ki-67, Ki-84 and Ki-100 are all armed with.

[Pongo]

Why would it be 10 times easier to land hits with a MG? Only if you have 10 times more of them. Want to mount 40 mgs on a fighter?

[Tails]

Originally posted by SunTracker
No fighter mounted 8 cannons in World War II though.  Highest I know of is 4 cannons.

What about the BF-110G2? 2 internal 20's, 2 external, and a pair of internal 30's... Now granted that isn't 8, but it's still nothing to sneeze at either.