How much runout is too much?

[Tim K]

I borrowed a Sinclair runout gage and checked some .260 ammo I loaded. I'm seeing TIR of 0.001" up to the occasional 0.007". Average looks to be 0.004".

Obviously, zero is good. What constitutes bad?

[Hoser]

More than 3 goes in the practice pile.

[Tim K]

Did you do some testing to come up with that number?

[Hoser]

Nope. Just a number I pulled out.

[Zombie Steve]

I know the Hornady tool basically measuring off the base instead of the side isn't going to be as accurate as the Sinclair, but you can correct runout with the Hornady tool. The point is to get them all the same. If I get more than a couple thousandths, I'll give it a bump. If it's 6 or 7 off, I'll just pull it and try again later. You will dent a thin jacketed target bullet trying to push too much.

Square up your dies (put washers on your shell plate, raise the ram so it contacts the die and takes the slop out, then lock it down) and you'll rarely have a problem. I like and use the o-ring as well.

http://www.accurateshooter.com/technical-articles/reloading/o-rings-on-dies-may-reduce-run-out/