Testing calibers for recoil
For new shooters recoil can be intimidating, and cause flinching, for older shooters those little impacts can add up over time. When I got in NRA High Power, I had a soft recoiling 30.06, but everyone said if I was serious I'd go to 308, Well my 308 had a pretty good kick, and my performance went down, so I went to 223/556. But the flinch I had developed was so bad that if I didn't use plugs and ear muffs, when the guy beside me fired, my whole body flinched. Didn't even know I was doing it, but an RO ask me after a string of rapid fire prone if I'd had a seizure. It took about a year to get past that one.
Then a couple of years ago, I put about 300 rounds of 45 auto down range, and felt like I'd been hit by a truck, I blew it off as anything but shooting, after all I had fired over 500 rounds of 45 in a day without any problems, then a month later ran 200 rounds of 45, next morning wrists, elbows, shoulders hurt like hell. Recoil does have an affect and after 50 years of shooting my body was telling me. So these days I keep it at light 9 mm's, and 223 and take something before extended range periods. Sometime in the last couple of years Todd Jarrett had to get reconstructive surgery in the elbows and shoulders, due to the tens of thousands of rounds he had fired over the length of his professional career. Recoil takes it toll.