Thats interesting since they’re still in use today nthere just called the M40A5. Never like the 7.63x51 it’s pretty much a mediocre round compared to many others out there. The 300 Win Mag is gaining popularity as well as some of the Lapua rounds. Of all the calibers being used today by our US Military I’d put it at the bottom rung of the ladder.
7.62x51. Fat lazy finger and maybe wisky.