Having fired many real guns, shotguns, rifles, a few pistols, and bows (my school does archery), I can safely say that
A) he is full of bullshit if he can't fire a .22 and if he thinks its too heavy. Yea, some are heavy, but go for a 30-06
2) Wilson is right, though I've never been on a firing range for that long, I have sat in a tree stand for hours on end having to use restroom. And it was cold. Really, really cold.
III) Kick is a *****, even with a 20. gauge, you can get hurt if your don't hold the gun right. Especially with single shot, seeing as they're lighter. 30-06 don't have much kick becuase they're so damn heavy.
quatre) Airsoft and paintball are nothing like the real thing. OK, maybe a little. But not really.