I spent a frustrating day at the range today.(still better then work!)I tried loading 500 grain FN cast bullets with 56.0 grains IMR 3031 and got basically 10" groups?at 50 yards! Did not have a chronograph set up today, but I estimate about 1700 fps with this load. This rifle consistently shoots 2" groups at 100 yards with jacketed bullets. But was trying to get a reduced cast bullet load that won't loosen my teeth.

Does anyone have any ideas. Thanks for your help.

BigBullet

I shoot a 420gr fn bullet in my .458, get 1 to 1.5" groups at a 100yds, have used powders from greendot, to H-4227, all worked well.