Dad: I'm sorry I get a little brash sometimes. I own upwards to 40 different guns, ranging from .338Win Mag down. I own semi-autos, pumps, bolts, lever guns, and single shots. For the last three years I have only carried single shots. During the fall hunting season (August & September) I carry a TCR in .338 mag, not to kill Moose and Caribou, a 30-06 does that just fine, but in case I run into a Grizzly I want to be sure I have enough gun. The rest of the year I carry a NEF Handi in 30-06. The 30-06 is adequate for anything in North America, but I feel it's marginal for the big bears here in Alaska.
When my 76yr old Dad came up to hunt Moose a few years ago, I discovered he did not know how to shoot a high powered rifle. Dad had never hunted anything larger than squirrels and rabbits. My Dad was one of the best marksmen I knew with a .22LR. But he had never shot a high powered rifle and was really concerned about recoil. I had to take him to the range and teach him how to shoot differently. Once he learned proper technique he really enjoyed my .35 Whelen Handi. He took that gun out and shot a 54" Moose.
Basically what I'm trying to say is, it does not matter how big the gun is, take it out and shoot it. Start off with a few shots the first time then increase it. Practise, practise, and more practise. Then one day you will realise you don't notice the recoil, you're just concentrating on the shot. Now I'm not saying go get a .460 Weatherby, or a 416, let's be reasonable. But anything from a .35Whelen, 30-06, 308, 7mm08, or anything comparable should be just fine. Remember to role it into the pocket of your shoulder, and use the left hand (if your right handed) to pull it back into the shoulder firm. Then concentrate on the gentle trigger squeeze. Good Luck! Rog