I have a mountaineer and a disc extreme in 52, I have purchased the conicals from the guy on gunbroker and have purchased alot of other cast bullets to plink from him can't beat the price, I am new to full bore conical shooting but have used the ones from the guy with good results, using Alliant BlkMZ, 60-65 grains by volume, and have shot all three weights he carries, the problem I encountered was what type of wad to use, I have tried the 54 cal and 28g, I have read that there is a 32g wad available and that would be one to try, no real big difference in the 54cal or 28g wads with poi but not owning a 54 I got a few from a guy at the range he didn't have use for so I used them up, the weather changed in Az and got real hot, so shooting has slowed down for me I get out and shoot for a half hr or so and only concentrate on saboted bullets at the time, 110g by volume of Alliant BlkMZ with a knight grey sabot and a rainier .458 350grain FN and a w209 primer produces one nasty hole at 100yards, in my mountaineer and disc extreme both are topped with a Burris Fullfield II 3x9x40