In olden times (JFK era) the National Guard was actively soliciting my high school buddies.
We went out to the desert driving the tanks over the obstacle course, fired mortars, and I got a 100 round turn with Ma Deuce Herself on a tripod. It was good.
Thrown some heavy lead from 58 cal front stuffers; competed IHMSA with FL308 XP-100; developed some rather edgy 44 mag revolver rounds with Elmer Keith's recipe; high cap modern 12 gauge stuff; perhaps the heaviest handgun load I've handled was that double charged 38/45acp pistol my buddy had screwed up loading....
Did turn down an offer to shoot a guy's TC in 444 factory load. Shot & enjoyed the '41 mag super' or whatever they called it...325g "41 mag" long case at 1400+fps....think it was in a Dan Wesson revolver built to IMHSA specs. Downright accurate & pleasant besides.
One of the nastiest recoils I've ever encountered was a nice looking SxS 20 gauge Ithaca cut to 20"....lovely patina, great weathered stock, cowboy gun, appeared as if it had been laying in your great great uncle's buckboard since about 1930 or so...wretched recoil with standard loads.