Howdy, boys. I've been shooting cast bullets for forty years but mostly in muzzle loaders, lever guns, BPCR, and revolvers. Recently I bought a pre-model 70 Winchester--1939 target model with a with non-factory heavy barrel. With a unertl 15x scope off a solid bench it shoots 1-2” five shot groups at 100 yards using Harris 2400 and Red Dot loads with a 200gr bore rider gc bullet. About 50% larger with a 150-170 fn bullet.
I can shoot the rifle pretty well at 50 yards with Lyman iron sights, and I figured I'd have some fun in the ground hog postal match. I tried shooting a number of pb bullets with loads I got from Harris writings and off this site, but with terrible results. 4-6' groups, or worse.
I need any help I can get finding a respectable load to shoot in this match, and I don't have much range time to work something up.
Any help will be appreciated.