How funny someone else should post this just today! Just got in from sighting in my FA M83 with 335 LBT's at 1250 fps in a .454 Casull. I'm in the same boat. Man but is it ever hard to shoot groups anymore. Not totally incompetant just DEGRADING.
I'm OK at closer ranges but as soon as we pass 25 yds I have a hell of a time focusing on the sights. My vision is fine, but have to use the cheapo +1 reading glasses to see small print clearly.
Only alternative I can see other than a scope is to just shoot BIG stuff at CLOSE range. Thats MY solution.

FN in MT