Ok, lets say any gun with a good recoil. That could mean a really light gun, or a hard hitting caliber. A 30-06 has about 21 lbs of recoil. That's about the maximum comfort level for most people. When you start to get past that. Flinching can happen

The reason I was talking about magnums, is that's what was being discussed, and they're mostly all past the normal comfort level. It may not seem like recoil is bothering someone at first, but it builds up, and soon the body is reacting to it.

I'll give you a good example. I used to be on the Trap Shooting tour in the 70's. I had no problem shooting a 12 gauge all day long with no effect from the recoil. A Timney used to come to the shoots with a trailer that was a machine shop. he working on everybody's guns at the shoots. He had done some trigger work for me. One day it felt like the trigger was locking up. I brought it to Al to check out. After looking at it he said it was fine. I didn't believe him, and went out to shoot. It felt like it locked again. he checked it again, and then laughed. He said..your flinching! I said no way I was pulling the trigger as hard as I could. he finally convinced me to put a release trigger in the gun. I did, and I never had a problem again. My body was reacting to all those thousands of shots, and stopped me from pulling the trigger. I would jerk the gun like it was recoiling, but couldn't pull the trigger. The release trigger relaxes the muscles instead of tightening them, and I didn't flinch anymore.

Flinching can grab anyone at anytime. The more the recoil. The easier it can happen.