Something I've wondered about for some time, why the Besa machine-gun used in British tanks was chambered for the 7.92mm round. Why wasn't it chambered for the .303" round, was there something about the gun which precluded this? The ZB33 was able to be chambered for the .303" in the Bren, so why not the Besa?
I certainly don't know the reason but sometimes changing the round of an automatic weapon can be trickier than expected. The US attempt at a .30-06 MG 42 was a flop. T24 machine gun - Wikipedia
The .303 was rimmed, 7.92 was rimless - the former was probably not suitable for the mechanism if the rounds were pushed forwards through/out the belt into the chamber. Remember that on the Vickers, .303 rounds were drawn backwards out of the belt, then pushed forwards into the chamber
It is asserted at: Besa machine gun - Wikipedia that “it was considered by BSA and the Ministry of Supply that the industrial, technical and supply difficulty of converting the design to the .303 round would be more onerous than retaining the original calibre, especially given that the chain of supply for the RAC was already separate from the other fighting arms of the British Army and the round was not changed for British production.....”
I think that I have mentioned this on the forum before. Some years ago I gave a talk on the BSA Factory in Redditch, I lived 500 yards from the site and our house had a crack down the rear wall caused by a bomb that missed the factory about a mile from the house, the whole area shook and our quite substantial air raid shelter with concrete roof was severely cracked. Fortunately it was the only one during the whole of the war although later locals and the press get mixed up with stories of the Birmingham Small Heath Factory bombing which caused much damage and casualties. My parents both worked there after the war. Attached are my notes that I used. There are a number of websites regarding the BSA but some are quite modern with a certain amount of "wishful thinking".
Thank you, all of you, for your replies, I did wonder if it was the design that made a change of calibre not considered, and the RAC having their own supply chain lessened the possibility of error. I wonder how often captured enemy ammunition was used?
I don't have the figures to hand but the Allies captured an awful lot of kit when the Afrika Corps had their "Dunkirk moment" at Cap Bon Tunisia May 1943. One British Artillery Regiments experience with captured German Weapons: "The object of this move was to cut off all Jerries West of us from Cap Bon, to allow the Americans at Mateur to catch them up. It was still raining and pitch black and the maps were bad. But we eventually got going nose to tail. Every man armed to the teeth with Tommy Guns rifles, German Lugers and MG34’s and piles of grenades. We had enough ammunition to wipe out a division!
With belt-fed MGs it isn't just the cartridge which needs to be compatible, the belt design does as well.
One advantage of sticking with 7.92mm was that it could use captured ammunition. The British initially didn't make an AP round for the Besa, which was necessary for penetrating the shields of anti-tank guns, and so after Operation Crusader it was captured German AP that was put into the belts for this purpose.
Speed of adoption was considered more urgent than re-chambering the weapon according to the minutes of the Small Arms Committee. The search for an air-cooled weapon dragged on for several years through the 1930s, partly to give Vickers a chance with their continually-failing proposal. A British-designed and made weapon with export potential would have been preferred. By the time adoption and licensed production of the BESA was obvious and proposed the war clouds had gathered and the need to replace the Vickers as an AFV weapon was urgent. The different cartridge was considered acceptable. 2 guns were purchased from ZB in 0.303", essentially hand-built prototypes. So it was possible. How they solved the forward extraction from the belt with a rimmed round I do not know. Royal Armouries NFC have one - if not both - of the guns so it should be known or possible to establish how. The guns were fairly lightly tested with 800rds per gun and suffered 4 stoppages in total.
Something else I forgot in the context of captured ammunition was that the BESA would not function AFAIK with the all-metal belts used by German MGs. The original BESA belts, sometimes described as unique, were metal clips attached to a canvas belt rather than linked all-metal clips. All-canvas Vickers-type belts were later used. So it is conceivable that captured German cartridges might work but that they might need to be re-loaded into British belts.
Isn't that a very high failure rate? I believe the standard for the US M60 was six or seven thousand rounds between stoppages
It is Dave, but different times, different wars, different acceptance levels of what was deemed servicable. Hope you and yours are all well there across the water. Kind regards, always, Jim.
Looking back at this thread I recall that many workers thought that they were making parts for the Bren. Possibly due to the flash eliminator on the barrel. These were probably machinists and office workers like my mother, a Comptometer operator in the Wages Dept. comptometer operator definition - Google Search My father worked for the Railway, often loading light weight armoured vehicles onto flat wagons during the war, driving ARP ambulances at night. Much later my mother became a Radiographer in the BSA Precision Castings where they made engine blades for jet aircraft. I have little doubt that the workers assembling and testing them knew what the weapon was but not encouraged to speak about them. (The Walls Have Ears being a popular slogan).
