....The reason I ask is that I have two 30-06 rifles, and strangely the M1 Garand outshoots the Remington 760 thus far. So, how big a role does bullet orientation play? I have set the OAL to match the Remington, and slugged the bore, which came out at .309", this shoved me to using unsized bullets at .312" diameter. Still I have **** for group size. I am using the Lyman Cast Bullet Handbook for loading reference.
BTW- the Remington has turned in .680" 3 shot groups at 100 yds before with jacketed bullets. Oh, and I am shooting water quenched WW at about 13 BHN cast in a Lee 160 gr. FPGC.