hey buddies, after much time and $$ I found a load MY standard brrl likes:
43gr(IMR4350)+ 80gr spitzer.. getting 3/4" groups(center to center) @ 125yds
FYI: my handi doesn't group as well with 100gr bullets which was my 1st choice when beginning this never-ending quest. tried 3 different powders of varied charge weights & none grouped as well as the 80's did. Research on the problem seems to suggest the 1-10" twist may not be enough spin to stabilize the longer 100gr spitzer. Sierra wants 1-9"(or faster) for the 105gr matchKing bullets..
I'm slightly dissapointed that the 80gr is so close to the 62gr that I shoot with the 223 but after reading on this forum how some 243 handi's WON'T SHOOT I'm just relieved to get tight groups