Question on loading

[Varmint Hunter]

You can't directly compare a world-renowned shooter, who FL resizes his cases, to a recreational shooter who is using over-the-counter, production grade dies. The pros who use FL dies have them made to precisely match their chamber, possibly with the same reamer. When properly adjusted, they will minimally resize the case for a perfect fit.

Standard production dies can grossly over-resize a case leaving a ton of slop in the chamber when the case is loaded. Generally, insipient case head separation is caused by excessive resizing. High pressure loads will accelerate the case head separation issue. While it's possible for a careful reloader to adjust the shoulder setback, you have no control over the change in case diameter. Production dies must be capable of resizing brass that will fit in any SAMMI chamber regardless of how loose or tight it is.

We can't always follow the lead of today's top shooters unless we are using similar equipment.

 

[Horse1]

You could use an 8MM expander ball, neck them up, then partial neck size back down to .308 until you crush-fit and headspace on a false shoulder on the neck. You'll have the case-head firmly planted on the bolt-face. The only thing that can happen @ that point is the case fills/forms-to the chamber when fired.

 

[Lenny Foffa]

That's a really great question!!!!! It may not be completely necessary, but at least one Fire forming session wouldn't hurt ! IMHO . I have many bench rest friends that Must Fire form their cases prior to loading and the groups some of them shoot during the fireforming session are really impressive! Many .3xx and even some .2 XX groups! Try 3 or 4 groups of 3 , Save the targets and measure ! That will give you some idea of how your rifle shoots those rounds ,in your hands ! Then you will know !

 

[BRADMOTO]

Ok now that I have determined my load and my seating depth with brass fired from my rifle a couple times my question is what do I do with new brass (same lot)? Do I just load the virgin brass as previously determined to be the best or do I waste some components and fire form it all?

I've not seen a just noticeable difference in precision between fireformed cases and virgin, even when they were .020" different. My OCD irrationally fueled by the internet mandates though, that I chamber/install my barrels with only a .002 growth of the case shoulder so when I FL size them back .002 they fire like virgin brass. Ergo, virgin cases and fired cases are the same. (Enough)