Bushing selection

[roughneck]

Hey folks,

I've just recently found the time to clean up the necks on some twice-fired lapua brass.
After the next firing I'd like to neck size them.

I have measured the neck of a loaded round.

What is a good rule of thumb when it comes to selecting a bushing?

Do I want it smaller or the same as the loaded round neck diameter? And how much?

Thanks

BTW, it's a 6 BR.

 

[Bart B]

For 6mm caliber, probably 1 or 2 thousandths smaller than a loaded round's neck. Maybe get one of each then do some good tests for accuracy.