Oh wait, i read it again, the Marine was you. Did you have an answer for how the Russian Army did so well with a .31 cal pistol? Not to mention Wild Bill Hickok did pretty well with a the equivalent of a 380.
But hey, nothing wrong with a 45, but ive seen a few people surprised when their death ray turned out not to be a death ray. Some underestimation happens with 30-30 and M-1 Carbine.
The “.31 caliber weapon” the Sovs used was the 1100 round per minute, 71 round magazine PPsH-41 submachinegun. You pour that many rounds at somebody, they’re going to get hit, lots of times.
I fired the NVA version of it and was an excellent weapon - but it isn’t a pistol.
Any pistol works fine - even the little bitty .25 - but you really want the bad guy to drop like a sack of fertilizer, first hit, use the .45.