I have a abolt by browning in a 270, I also have a bad shooting wing (shoulder problem). I have no problem plicking off 20 plus shells with this rifle in a t-shirt.

What does he have or has he shot prior? Is it comfortable?

You/He may want to consider a 7mm-08 they are very light in recoil and a great caliber. I assume this is mostly a deer gun? The 7mm-08 kicks less than a 270 and as whitetail/deer gun will be great. Many manufacturers offer this chamber. Others would be a 257 roberts or 260 rem., I have read and heard nothing but positive about these calibers, with recoil being very light and a target shooters dream. The only down fall would be if moose or elk is on the menu they may leave a bit in that department. However for deer they would be just fine.