Mr. Williams, quick question

[ramzey]

I walk thrue your website and have one question

Do you think US choice .50 M2 for fighters could be named disaster? or totally wrong choice?

im thinking about P47 example

best regards

ramzey

[Karnak]

I can't see how it could be seen that way.  banks of .50s are adequate to kill single engined fighters and that is the lion's share of what we faced.  The rest made up of heavier fighters and medium bombers, unprotected in the case of the Japanese.  Facing the odd He177 or H8K2 now and then doesn't justify calling the .50 a disaster by any stretch of the imagination.

[Sikboy]

I agree with Karnak,

The "Ideal Fighter Armament" Article on Tony's site is predicated on fighters that are intended to fight both Bombers and Fighters. The Implication, I believe, is that the MGs are sufficient for fighter work.

-Sik

[Sikboy]

Also check out the Plane loadout section of Figther Gun Effectiveness which gives some numeric values to different loadouts. In general terms the 6 and 8 .50 loadouts acquit themselves pretty well.

-Sik

[HoHun]

Hi Ramzey,

>Do you think US choice .50 M2 for fighters could be named disaster? or totally wrong choice?

A poor choice (though the US didn't have much of a choice actually).

However, definitely not a desaster. The price they paid was extra weight, and - in single-engined fighters - trajectory problems caused by convergence/divergence.

Here is a comparison of the 12.7 mm MG to other weapons on an "equal firepower, equal ammunition energy" basis:

1x MK 108 - 87 rpg - 111 kg - 221% firepower - firepower per weight: 900%
1x MK 103 - 75 rpg - 210 kg - 180% firepower - firepower per weight: 387%
2x MG 151/20 (MX) - 187 rpg - 164 kg - 124% firepower - firepower per weight: 342%
2x MG 151/20 - 207 rpg - 172 kg - 112% firepower - firepower per weight: 294%
2x Hispano V - 212 rpg - 188 kg - 109% firepower - firepower per weight: 262%
2x Hispano II - 206 rpg - 201 kg - 94% firepower - firepower per weight: 211%
3x MG-FF - 149 rpg - 235 kg - 103% firepower - firepower per weight: 198%
12x Ho-103 - 302 rpg - 400 kg - 95% firepower - firepower per weight: 107%
5x MG 151 - 239 rpg - 428 kg - 97% firepower - firepower per weight: 102%
10x MG 131 - 311 rpg - 413 kg - 93% firepower - firepower per weight: 102%
8x ,50 Browning M2 - 250 rpg - 452 kg - 100% firepower - firepower per weight: 100%
25x Browning ,303 - 399 rpg - 549 kg - 96% firepower - firepower per weight: 79%

You can see that with an equal ammunition load, the P-47 armed with 8 x 0.50" carries 452 kg of weapons and ammunition, while armed with just 2 x MG 151/20, it would carry just 172 kg for the same firepower.

That means the P-47 is penalized by the weapons choice by 280 kg or 617 lbs. Considering its take-off weight of 13300 lbs (P-47D-21, 8 guns, full internal fuel), 617 lbs were a noticable burden the pilots sure would have liked to get rid of, but not really that important for the overall combat effectiveness of the type.

Regards,

Henning (HoHun)

[Angus]

For a fighter vs fighter, even 4x.303 are enough, if one can bite itself to the tail of the other well enough.

Remember that some 2000 aircraft fell pray to the .303 in 1940

I have an excellent first-hand account from where a Pilot peppered an enemy fighter to the extent of crash landing with just 2x303's.

Can type it up or give the source if you like.

But when it comes to bombers....CANNONS PLZ.....

[Karnak]

I disagree Angus.

The .303 was lacking against all warplanes as armor was added to the vulnerable systems.  Even fighters would have been dificult to shoot down after the fuel systems and pilot were protected, and in fact that was noticed.

Tuck and Malan, while obviously considering bombers too, both wanted cannons.

And I would point out that being glued to your opponent's tail for an extended time while you slowly needle away at him gives his wingman a great opportunity to blow you away in a fraction of a second with his 20mm armed fighter.

[Tony Williams]

Just to endorse some of the earlier comments: the selection of the .50 wasn't optimal, but it wasn't a disaster. 20mm cannon were better for all purposes, 30mm against tough bombers. I think that the following phrase in the 'Fighter Gun Effectiveness' article sums it up:

"To sum up, the preferred US armament fit was effective for its purpose, but not very efficient by comparison with cannon."

Tony Williams: Military gun and ammunition website and discussion
forum

[Angus]

Karnak.
The .303 is a rifle caliber peashooter, no dispute.
But for a totally unprotected target as many were in 1940, it was quite ok.
Even as late as in 1942/43 in Burma, some RAF pilots had 303's removed from their Hurri IIB's, i.e. 8 guns were more than enough instead of dropping top speed for 12.
But they were fighting unarmoured planes, so that's why.

BTW, Bader preferred the 303, taking reliability and ROF instead of the cannon.

But in 1941 the Hizooka was alredy quite reliable, so I'd say he was a tad conservative

[Tony Williams]

It didn't take armour to stop the .303. This is an extract from 'Flying Guns: WW2':

"The test then changed to shooting at the rear of the long-suffering Bristol Blenheim at the same distance, involving penetrating the rear fuselage before reaching the 4 mm armour plate protecting the rear gunner, which was angled at 60º to the line of fire. The results in this case were reversed; 33% of the .303" rounds reached the armour and 6% penetrated it. In contrast, only 23% of the 7.92 mm bullets reached the armour, and just 1% penetrated."

In other words, most rifle-calibre bullets fired at even a small, lightly-built bomber like the Blenheim were deflected or absorbed by the structure.

Tony Williams: Military gun and ammunition website and discussion
forum

[Angus]

Oh, for the flip-side:
"I lead the squadron behind the Messerchmitts and blew up their leader with my first burst, before attaching myself to his wingman who must have been a novice as he took little evasive action, and notwithstanding my cannons jamming, I peppered him with my two machine guns from minimal range until my DeWilde set him on fire.
He struggeled into cloud cover where I lost him, and maybe he eventually got home, but I thought more likely, as the boys did, that he joined his leader in the mountains below."
Anthoney Bartley, 29 dec 1942, 111 sqn leader.
One victim is confirmed, Gunther Eggebrecht II Jg51, shot down and wounded.

So, the cannons quickly blew up a plane, but yet the humble 303's still managed to pepper another one.
Well, the DeWilde made a lot of difference, of course.

BTW, the cannon jams at that time were largely due to lack of maintenance, - lack of groundcrew lead to the pilots reloading their own guns, which they were not trained for.
Bartley had 2 303's removed in order to lighten the plane.
So, he kept the other two, just in case.

[Tony Williams]

Oh, the 'De Wilde' was relatively effective, all right. This is another quote from FG:WW2

"Comparative British tests of British .303" and German 7.92 mm incendiary ammunition held in 1941 against the self-sealing wing tanks in a Blenheim bomber, fired from 200 yards (183m) astern, revealed that the .303" B. Mk IV (based on the First World War Buckingham design) and the 7.92 mm were about equal, each setting the tanks alight with about one in ten shots fired. The B. Mk VI, which contained 0.5 grams of SR 365 (a composition including barium nitrate) was twice as effective as these, scoring one in five. The 7.92 mm API completely failed to ignite the tanks."

Of course, these shots were all carefully placed from a fixed mounting to ensure they all hit the target. In combat, only a tiny percentage of the bullets would have hit the aircraft, let alone the fuel tanks, so you have to fire a lot of bullets to be reasonably sure of setting them alight. Which is the problem - while you're hosing away, you're vulnerable to attack yourself.

TW

[ramzey]

Thx, Mr Williams
one more question
US try to fit 20 mm cnnon to f4u, f6f, p51C but postwar F84 had .50 cals onboard too, reason was effectivenes of mg or lack of technology in production of cannons?


ramzey

[Karnak]

Angus,

I know AH is not reality, but it does mimic it to some degree.

The A6M2 can kill F4F-4s with it's two 7.7mm machine guns, I've done so.  However if there are any other F4F-4s in the area it is nigh impossible to succeed at doing so because while the A6M2 is glued to the F4F-4's tail it cannot use it's superior manuverablity defensively.  If another F4F-4 moves to defend the targeted F4F-4 the A6M2 pilot needs to be alert to that fact and break off immediately or be shot down very quickly by the six .50 cals carried by the F4F-4.  It takes too much time in anything other than a one on one to use the 7.7mm guns exclusively.

[Furious]

Which loadout would have preferable for strafing, 2 20mm  or 8 .50 cal?