How good is your base?

[cstrickland]

I cast for 9m action pistol . I shoot action steel matches. I cast , water drop, powdercoat water drop, size and load. I only cull out anything that does not have fill out be it driving bands or a rounded bottom. I typically have very very few. Maybe only 1- 2 per K . My bottoms some times have small nibs . I have even had ones that caused the bullet to sit slightly off when powder coating, and I have never noticed any difference for what I shoot.

unless you are shooting for bullseye or similar then you should be more than fine.

[cainttype]

The OP states the flashing is from sizing in post #1.... Sizing base-first will eliminate base flashing from lead displacement.

[Bazoo]

Polishing your sizing die will eliminate help flashing from sizing.

[FabMan]

Just to clarify, the flashing starts at the mold, at the base. My nose first push thru sizing dies take that extra material and curl it down creating an edge. I’m talking about very small flashing, not something obvious you would return to the pot. Check out your flat bases with a 5x magnifier and see how imperfect some are. Gases exerted on these imperfections as the slug leaves the barrel may cause issues, especially with longer range rifle shots. I’m not a perfectionist by any means, just looking for an easy way to smooth out the base for bulk casting. I did try a RCBS motorized outside case chamfer tool and that worked somewhat well.

[charlie b]

If you need a 5x magnifier to see the flare I don't think it will be a problem unless you are shooting several hundred yards, like with a .45-70.

My rifle bullets get a gas check, seated square to the bullet base.

Take your bullets and shoot them and see if you have an accuracy problem. Compare to commercial loads. Sorry, noticed you already did that, 20% bigger groups with your cast. 1" compared to 1.2" I'd probably be happy with that.