Just FYI, they made only about 12,700 of those rifles and it is estimated that less than 2000 survive. They were not liked, mostly because of the weight, which ran to 11 1/2 pounds. It was also very complex and difficult to keep clean. The odd operation, with a bolt handle, was not especially liked. In several respects, the German army specifications were not well considered, especially that there be no hole in the barrel and that the rifle must be able to operate as a bolt action if the gas system fails. The former requirement seems to have been common military thinking at the time, as it was also imposed by the U.S. Army on John Garand, the result of which was the "gas trap Garand".
The Wikipedia article on the G.41(M) is incorrect in saying that it uses the Bang system. It does not. The Bang rifle used a piston that was pulled forward by the gas, and was attached by a wire to a pivot in the receiver. The pivoting arm threw back the cover, which operated as the bolt carrier. The G.41(M) and G.41(W) both used a piston around the barrel attached to an operating rod. The G.41(M) used a rotating bolt which was unlocked by the carrier; the Walther used "flap" type locking lugs moved outward to lock when the carrier went forward.
I have been fortunate enough to have fired both rifles. The Mauser seemed awkward and heavy, though the extra weight reduced felt recoil considerably. It was very well made, with forged and machined parts, and that one had a beautiful finish. The Walther rifle, the G.41(W), though it had stamped parts and looked rougher, seemed more user friendly, but that may have been because I was used to the G.43, which was a modification of the G. 41(W). When the Mauser G.41(M) was finally rejected, the (W) and (M) were dropped and the Walther rifle became the G.41.