rcgerchow
I have the same ringing problem you are talking about, probably not as bad but it is there. ALL of my life I shot ran chain saws, did all that noisy stuff without wearing ear protection - no big deal... except a few years ago I went out to site in a A&H and I set up right off the tail gate of the pickup. I shot most of the afternoon without a problem but that night the ringing started - all that shooting with the concussion coming back of the pick box did me in... I still shoot but I don now need to wear good ear protection. I still hunt and I hunt without ear protection, because i believe out in th open i can shoot 1 or two shots and not have a problem and so far everything has been ok.
But, to the question - i really do not think there would be any difference between the concussion (noise) between to the two guns so I would stay with the 50... if anything the 45 might be sharper..
Just my 2 bits...
Good luck to your freind...