The first IPSC match I attended, circa 1994, featured a guy reloading his Broomhandle Mauser with stripper clips. So, what could be wrong with using a P-38?
When I started, I shot a G.I. Colt .45 that had been fitted with better sights and a trigger job. I had a belt-full of 8-round mags, and one, 11-round "big stick" that I'd move around on my belt so it would come up when I needed the extra rounds. Those were the days . . .