Why Did The RAF Use .303 Caliber Machine Guns in WW2? The Surprising Answer

[wuzak]

 

[Gnomey]

Good one!

 

[Barrett]

Without scrolling thru the video I'll just note:
The RAF had warehouses full of .303, and whatever reason(s) got considered (rate of fire, density of pattern, etc) that had to be Hewge.
Similar situation in the U.S. with tons and tons of .30-06, which is why the .276 M1 Garand round was ignored. Fortunately, the US signed on to the .50 caliber which gained global air superiority.

 

[Shortround6]

The RAF had warehouses full of .303, and whatever reason(s) got considered (rate of fire, density of pattern, etc) that had to be Hewge.

At times, but by 1942/43 the British were using mostly AP and incendiary bullets and had stopped using the Infantry bullets. Even during the BoB only about 37% of the ammo was "infantry" ammo.
While ground MGs used tracer it was not in quantities that Aircraft MGs did. Likewise AP bullets and early incendiary were pretty much special use ammo.

For the US in WW II there were 3 classes of .30 cal ammo.
1, Aircraft Machinegun
2, Ground Machinegun
3, Rifle ammo.

That was in descending order of quality. Nothing to do with accuracy. It was the quality of the brass casings.
If you have a head case separation in an aircraft gun the gun is out of action until the plane lands and an armorer can deal with it.
If you have a head case separation in an ground machine gun the gun is out of action until the crew (covered by other guns and rifle men) can open the gun up, use the broken shell extractor (or change barrels if one is available) and return the gun to action.
If you have a head case separation in a rifle nobody (except the rifleman) cares. A 1919 Browning is putting out 10-20 times the amount of rounds than the best riflemen in the company can do. They have to keep the MGs in action. Rifleman can often pick up a rifle from a casualty.

Using 12-20 year old ammo in aircraft guns was not a good idea (no matter what the treasury men thought)

As mentioned in the video they was also a cost (both money and lost production) in retooling the ammo factories.
A reason the Germans went to the 7.9mm Kurtz round for the MP 44. They could use some of the same tooling used for the 7.9 X 57 ammo.

 

[buffnut453]

Fortunately, the US signed on to the .50 caliber which gained global air superiority.

I'd amend your statement to read "Fortunately, the US signed onto the .50 caliber and persisted to resolve operational problems with wing installations of the weapon so that it could gain global air superiority."

There's no way the RAF could have used the .50 cal mounted in fighter aircraft wings in 1939 or 1940. Weapon production wasn't sufficient, and wing-mounted installations were prone to jams (a problem that continued thru to the second half of 1942).

 

[Shortround6]

I'd amend your statement to read "Fortunately, the US signed onto the .50 caliber and persisted to resolve operational problems with wing installations of the weapon so that it could gain global air superiority."

There's no way the RAF could have used the .50 cal mounted in fighter aircraft wings in 1939 or 1940. Weapon production wasn't sufficient, and wing-mounted installations were prone to jams (a problem that continued thru to the second half of 1942).

British couldn't get the cowl guns to work in the early Tomahawks. Lt. Hubert Zemke was writing reports that June and July of 1941 about British complaints about the cowl guns suffering endless trouble.

 

[Mustangtmg]

The British used .30 Cal US (".30-06") BMGs in the Mustang Mk I (NA-73 and NA-83). There's no "easy" way for a .30 Cal BMG to "handle" that rimmed .303 British ammo. Secondly, because of the rimmed .303 case, a belt of ammo necessarily held fewer rounds of .303 per length of belt, than if the rounds were. 30 Cal US.

Spitfires, Hurricanes, etc and also bombers (with "flexible" mounts or turret mounts) were designed to work with the UKs own machine guns), had no trouble with .303 ammo because of the design of the ammo chutes, magazines, etc. The British decided that it would be a more simple, reliable "departure" from having machine guns that fired .303 ammo, to go with the .30 Cal US Caliber BMGs. This fact is specifically discussed on page 171 of Bill Marshall's (along with co-author Lowell Ford) book, "P-51B Mustang: North American's Bastard Stepchild That Saved the Eighth Air Force."

It would follow that the four .30 Cal US BMGs would "go with" the four .50 Cal BMGs that the Mustang Mk I came with from NAA. UK Mustangs (of all Marks) had features that were unique to their Mustangs, but the .303 Cal British weapon was not one of them.