The answer to the maximum bullet diameter depends on three things:
1, How big is your chamber?
2, How thick is the brass neck wall?
3, How big is the bullet?
I once bought some foreign hardball that had bullets 0.449" in diameter, but cases with necks so thick that I could not load a 0.452" in those cases without it jamming the chamber. From that experience, I would not go larger than .4525" with most normal brass. You might get to 0.4535" or even 0.454" so with R-P brass, as it has a very thin neck wall, or if your chamber is on the larger end of the diameter of the diameter specification. A smarter strategy is just to try them and fire them and see what diameter causes accuracy to peak.
