The heaviest I have shot in a 1 in 14 Ruger #1 was the 60 grain SP Hornady and Nosler 60 grain Solid Base bullets. I used them because the Ruger had a very long throat, and I wanted to get closer to the lands. We weren't allowed .22 center fires for big game back then, so I didn't try anything bigger. I am thinking the Nosler 64 grain bonded might work.
