ORIGINAL: sabinajiles
As I was finishing an evening of punching some paper recently, just for a lark, I tried some 300 grn REAL conicals in my .54 GPR. I used an over the powder wad and 90 grns Swiss FFg. I fired 4 rounds, from 50 yds, using cross sticks and cloverleafed 3 shots, with the 4th about 1.5" low and left. I was shooting into a stiff headwind which was causing some difficulties in stabilizing the rifle on the sticks, so I was shocked it shot so well. Maybe I just got lucky but I haven't had a chance to try them again, which I will do just because I am curious. My GPR shoots balls so well, and since the .54 ball will handle anything I am going to hunt, that I have no desire to use a conical for anything beyond occasional target shooting.
OK, it's official. I went out yesterday evening and tried this again. My .54 GPR will shoot 300 grn REAL conicals as accurately as it shoots balls. It actually seems to be more accurate with the REALs at heavy powder loads. I shot 30 rds, with up to 100 grns of Swiss FFg and 110 grns of Goex FFg, using an over powder wad with both, and it handled them all with outstanding accuracy.