I shoot 45 Cal White ML with either a 350 or 465 grain conicals with great accuracy. My 45's have a bore size of .451. I like to size my concials to 451.5. This helps ensures they will not move off the charge yet still allow you to easily push them down the bbl with one hand. I also found that a felt wad helps a little to squeeze a little more accuracy out of them. If you are having issues with Open sights, maybe try using a Peep Sight.