Hellcat and Corsair vs. Messerschmidt 109 and FockWulf 190

[renrich]

Zoomar, I have personally seen what a single 50 BMG will do to targets on the ground like trucks and Light armored vehicles. I also know what a fighter plane from WW2 looks like as well as once worked in a factory building rear fuselages of F101s. I feel sure cannon were more useful against slow big targets like four engined heavy bombers but I wonder if some LW pilots would have liked to have had six 13 mm MGs instead of the cannon against a fast small target like the P51?

[zoomar]

I really can't disagree that mixed MG and cannon armament carries with it poor ballistic consistency. Also, if the main opponent of the Luftwaffe were fighters and not 4-engined bombers, may pilots may have wished for 6 heavy MGs rather than a single 30mm cannon and 2 15mm. That takes me back to my original point that you really can't compare the armament of the F4U/F6F with the Bf109/Fw190 without considering the nature of their main opponents. The main opponent for the US navy planes were lightly built Japanese aircraft, while the German fighters' main opponents were heavy bombers.

However, the fact remains that the USAAF was virtually alone in retaining machine guns after all other nations switched to a mixture of cannon and MG's, or as the British did, to four 20mm cannon. Personally, I'd consider the armament scheme of the Tempest virtually ideal for a mid-late WW2 multipurpose fighter: four relatively fast firing guns with the same ballistics and explosive shells.

[renrich]

Quite a few Hellcats were armed with mixed cannon and mgs and a number of Corsairs were all cannon armed. Apparently the six 50 mgs was more suitable. However the F4U5 which was roughly contemperaneous with the Sea Fury was all cannon armed. The F8F was originally armed with four MGs but later was switched to cannon.

[Colin1]

However, the fact remains that the USAAF was virtually alone in retaining machine guns after all other nations switched...

...and if they didn't work for them, they wouldn't have retained them either; fighter vs fighter, 6 x .50s was a big punch.

[renrich]

People who are not familiar with the 50 BMG, I believe shortchange it. It is not nearly the same animal as a rifle caliber, not even magnums and elephant rifles. I can only imagine what six-fifties would do converging on the target having seen what a single will do.

[riacrato]

The Fw 190 had 4 20mm before any 8th air force bomber ever saw european skies. The MG 151 was designed as an allrounder aircraft cannon, never as a anti-heavy-bomber gun.

[tomo pauk]

...
Also, if the main opponent of the Luftwaffe were fighters and not 4-engined bombers, may pilots may have wished for 6 heavy MGs rather than a single 30mm cannon and 2 15mm.
...

Out of curiosity: what fighter carried one 30mm and 2 x 15mm (simultaneusly, of course)?

[davebender]

I don't think anyone is underestimating the .50cal machinegun. But the fact remains they don't have nearly the destructive effect of 4 x 20mm cannon or a 30mm cannon. That makes a difference in boom & zoom combat where you may only land 1 or 2 hits during a high speed pass.

[MikeGazdik]

Fighter vs bomber, the cannon is better. Bigger, slower targets, much more likely to get slower firing rounds onto target. And they cause more damage, which is needed on the bombers.

Fighter vs fighter, the large caliber machine gun is better. A much smaller, more agile, harder to hit target. Volume of fire is more important. Multiple rounds from a .50 will certainly do damage. Even if you don't "kill" the enemy plane, he will likely try to disengage and go home to lick his wounds. (if the plane makes it home) But the plane is put out of that battle, so the weapon was affective.

I think the old handgun saying " I'd rather hit with a .22, than miss with a .45" comes to mind.

[riacrato]

Disagree strongly. No evidence that 4x20mm was in any way inferior to 6x .50cal in the dogfighting role.

[Vincenzo]

Fighter vs bomber, the cannon is better. Bigger, slower targets, much more likely to get slower firing rounds onto target. And they cause more damage, which is needed on the bombers.

Fighter vs fighter, the large caliber machine gun is better. A much smaller, more agile, harder to hit target. Volume of fire is more important. Multiple rounds from a .50 will certainly do damage. Even if you don't "kill" the enemy plane, he will likely try to disengage and go home to lick his wounds. (if the plane makes it home) But the plane is put out of that battle, so the weapon was affective.

I think the old handgun saying " I'd rather hit with a .22, than miss with a .45" comes to mind.

also some 20 mm have high volume of fire and a (limited) multiple hits from a 20 was sure destroyed fighter

[zoomar]

Quite a few Hellcats were armed with mixed cannon and mgs and a number of Corsairs were all cannon armed. Apparently the six 50 mgs was more suitable. However the F4U5 which was roughly contemperaneous with the Sea Fury was all cannon armed. The F8F was originally armed with four MGs but later was switched to cannon.

The fact that late war or post war US types such as the F8F and F4U5 adopted the same 4x20mm cannon armament layout as the British Hawkers (Temepest, Typhoon, Fury, etc) helps show that 4x20 cannon is probably the most versatile all-round fighter armament - and even the USN came around to this way of thinking. Sufficient RoF and number of barrels for effective dogfighting, yet packing the punch needed to damage key aircraft structures.

[zoomar]

The Fw 190 had 4 20mm before any 8th air force bomber ever saw european skies. The MG 151 was designed as an allrounder aircraft cannon, never as a anti-heavy-bomber gun.

True, but the Fw-190 was designed with potential European theatre fighters in mind (self-sealing fuel tanks, armor, strongly built, etc - as well as large multiengined British bombers). Further evidence, in fact, that the early decision to upgun the Fw-190 to a four-cannon standard (plus the two MGs) created a very versatile fighter, excellent in fighter vs fighter combat and mid-altitude bomber interception.

The four and six .50's mounted on most USN and USAAF types were indeed powerful enough to damage and destroy fighters, but I remain convinced that this standard was in part kept because the Americans never had to face a determined or effective bombing campaign, because they could easily take down most poorly protected Japanese fighters and bombers, and because they proved to be acceptable (although probably not ideal) against the well protected Fw-190, Bf-110 and Me-410 heavy zestorers they encountered in Europe in conditions of general US air superiority. I'd argue that only with the P-47 D, with its eight .50 cals, did the USAAF have a fighter that equalled the hitting power of the Fw-190.

[Glider]

I'd argue that only with the P-47 D, with its eight .50 cals, did the USAAF have a fighter that equalled the hitting power of the Fw-190.

Sorry but the firepower of a P47 was about equal to a Spit with the E wing. The 190 had another couple of cannon.

Most people agree that the 151 was equal to the Hispano II used by the RAF so in short, the P47 was well behind the FW 190 in its firepower.

[renrich]

The points which I think are ignored by the cannon advocates are: The US fighters with 50 cals were mostly more long ranged than the other combatant's fighters and thus were more exposed to combat for a longer time. They could carry more ammo and had longer firing times. An escort fighter with no ammo is almost useless. The 50 cals were adequate in use against the EAs that were encountered in both the the ETO and PTO and their faster rate of fire, higher down range velocity and longer firing time made it easier to get hits. If a pilot has twice the firing time in his guns, he is more likely to hold the trigger down longer and make hits more likely.

There is no question that a hit from a cannon can be more lethal than a hit from a 50 cal but neither weapon's projectile is infallible. There are plenty of examples where US fighters received multiple hits from cannon and came home. I think an analogy that shows how a lighter caliber weapon is superior because of ROF and velocity is the Mig 15 which was armed with two 20 mms and one 30 mm. I have read that the 30 mm in the Mig was largely ineffective against the F86 and in Viet Nam, whereas the faster firing and higher velocity 20 mms did most of the damage.

The fact is that the AAF continued to use the 50 cal BMG in it's jets until well after WW2. The USN used 20 mms in Corsairs and Hellcats that were dedicated night fighters where the target was probably a slow flying bomber or recon plane, not a fighter.

An example of how the lower ammo supply of a cannon armed AC limited the usefulness of a fighter is the early war A6M with only 60 rounds for each of it's 20mms. At Midway, the effectiveness of the CAP of the Kido Butai was heavily influenced by the need of the Zeros to land and rearm.

To me, another analogy to the 50 BMG versus cannon discussion is the choice of shotgun shells when hunting geese and doves. Most hunters hunting doves, a small and fast moving target, use 7.5s or 8s because the density of the pattern makes it easier to get hits and those small shot are adequate to bring down a dove. Hunting geese you go to number 2s because the number 2 is adequate to bring down the goose. That number two is more than adequate to bring down doves but the pattern is much less dense and that pattern would make it much harder to obtain a hit. I believe that we all tend to think of aircraft weapons in WW2 creating a very small impact point at the point of convergence at the optimum range but the fact is that there are many factors which cause the projectiles to spread into something more like a shotgun pattern. The denser the pattern the more likely to get a lethal hit.