Yeah, the Gew 43 and all these other new-age weapons are just copies of the original Soviet warhorse, the SVT-38 (and SVT-40 and AVT).
It was so advanced when it came out, only some elite communist combatants could understand how to properly maintain and employ it as the advanced killing machine it was designed to be. (OK, so maybe that speaks volumes about the period Red Army, and not so much the weapon).
Anyway, it's interesting when you look at the history of small arms developments. The Germans (their engineers) were absolutely terrified of drilling a hole in the barrel for a gas port. They were like the anti-gas-port. They thought somehow this would weaken the barrel, and start hairline fractures at the port, unless cost-prohibitive awesome steel was used, etc...
The Americans did it with the Garand and it held up just fine. Then the Russians did it. They weren't as skeptical anymore, and it finally happened with the FG-42, a Luftwaffe (air force) development. After the abysmal failure of the Gew 41, it was redesigned as the Gew 43, with a gas port and the SVT gas system.
The SVT was still the better rifle, and many were captured and put into German service on the Eastern Front. They did this so much it was given a German designator, and their arsenals trained armorers in their inspection. Captured weapons were then inspected and arsenal-stamped for approval, time-permitting of course.
Soviet Naval Infantry, which by 1941 were
completely moderately armed with automatic weapons, to include SVT, AVT, PPD,
PPSh-41, DP lmg, and Tokarev pistols.
In my best Hudson voice, "Don't worry. Me and my squad of ultimate badasses will protect you!"
British forces at this time were
almost completely armed with bolt-actions, revolvers, fixed-position machineguns. (
Some Many did have the
Lewis gun Bren. 40,000 MkI Brens had been made and the MkII was rapidly being fielded, after nearly 23,000 Bren Guns were lost during the fall of France in 1940).
US forces were receiving updated (fixed/improved) M1 Garands by January 1941, and the US Army was considered fully equipped by the end of 1941 at 567,060 M1 rifles. US forces had the BAR as well as M1911(A1) pistols for all frontline units.
The USSR had produced 1,220,000 SVT's by the end of 1941, but
apparently Naval Infantry units were not elite enough to have received the bulk of them by 1941. Guard units were initially favored for SVT issue, over the targeted infantry forces distribution ratio of 1:3. In 1942-1943 Naval Infantry proved to be epic like Guard Units, and both were then given preferential SVT issuance. Neither stopped using Mosin Nagants completely though.
Edited due to inaccuracies pointed out by
RogueJSK (C&R Forum).