I have two new titanium shoulders and shared the same concerns as your friend. I have a shoulder shooting pad that works well, but I have also gone the route of smaller gauges. I can handle the 28 loads in my double as well as my Ruger O/U, but as Parabola mentioned I have also gone over to the dark side by frequently using a little gas powered auto in 28. It does well on early released pheasants and anything below that. I recently shot one my Ruger SFAR (black gun for those who are unfamiliar) in .308. The only thing I found I needed was a different butt pad and some more meat on my shoulders. I didn't realize how much muscle and tissue I had lost due to the surgeries. I am now in the process of building that back up. Soooo, I will stick with my recommendation for the 28 gas powered auto for your friend, at least for now. Of course, I also have acquired three or four new .410s JUST IN CASE!! I assured my wife when she caught me in my gun safe that the four new 410's were therapeutic!! She then assured me that her several new purses were the same!! Shoot the 28 routinely and learn to love it as you develop confidence in the new shoulder.
