Ok I don’t get it: Why did the Browning Automatic Rifle have catridge/magazines that only help 20 rounds? Why not 30? Or more? 20 rounds in an auto goes quick. Even on single fire it seems a bit scroogy to have just 20 pops.
Because a 30 round mag would be too big and stick down too far, making the weapon difficult to fire when prone. Earlier models of the M16 had 20 round magazines for the same reason, although since the 5.56mm is a smaller round the issue was more manageable and they eventually went to 30. Few 7.62mm magazine fed rifles were issued with a 30 round mag. The Bren gun and similar weapons tried to get around this by mounting the mag on top.
The later FAL, M-14, and G-3, as examples, also have 20-rd. magazines. Early Thompson submachine-guns has 20-rd. magazines. (This was increased to 30 rounds in 1941.) Twenty rounds was more than double the capacity of the M1 Garand, and four times the capacity of the Gew. 98 or Springfield.
As it’s name indicates, the BAR was originally conceived of as an automatic rifle, that could be fired on the advance while storming trenches. Giving it a humongous magazine would have made it too heavy and unwieldy. In fact it ended up being used more as a man-portable light machine gun than an assault rifle. Compare it to the Lewis Gun, which in American versions fired the same 30.06 cartridge, but which was intended as a light machine gun from the beginning.
Back then most rifles were fed with 5 or 10 round stripper clips. 20 rounds was already a net improvement over those. The British BREN gun (which served the same purpose as the BAR for the British army) only had a 30 round mag. The Chatellerault MG had 25.
Only the German MG 34s and 42s and the Russian Degtyarev ran with substantially higher ammo loads that that in squad assault weapon roles (MG 37/42s could also go belt-fed or use 100 round drum mags in HMG roles, but in those contexts the US Army didn’t use BARs)
The Canadian army issued an FAL with a 30 round mag and a bipod as a section machine gun.
As you can see from the picture, they are unwieldy when firing from the prone, which is the place where you want to do most of the firing, and made the gunner are huge target on the horizon. The huge mags were also a PITA to carry - a AK-47 style chest rig was issued to gunners that would endlessly wack them in the face when on the move.
A hijack if I may . . .
Wouldn’t the “cooling shroud” of the Lewis gun actually tend to keep heat in? I mean, to look at it at least, wouldn’t it prevent the heated air in the barrel from dissipating quickly (into the surrounding air)? Or, phrased conversely, wouldn’t it prevent relatively cooler ambient air from reaching the hot barrel?
Given that the shroud was actually used, my intuition must be faulty. I just am trying to figure out where I’ve made my mistake.
From the linked Wiki article.
Also from wiki.
I will bow to the more serious gun nuts on the board, but as I understand it…
The cooling shroud actually worked. The muzzle blast would force air in (out?) of the shroud, cooling the barrel. In other words, cooling air flowed through the shroud while the gun was firing.
Thanks for your answers (I am embarrassed for not seeing it addressed in the Wiki link).
Also it protects the highly vulnerable gas cylinder, which even a small dent in will stop the gun.