Custom die.

[Link]

We have all seen really good groups while fireforming on 1st fire.
Why not get a die made to speck new unfired brass? Why waite after 3 firings?
I;m sure some have tried this.

TY Don.

 

[Mark W]

We do three firings because it takes a more than one firing to fully form the case to the chamber. The idea is to not not unnecessarily work the brass during resizing. If we sized the brass back to its factory size after every firing, chances are good that it wouldn’t last as long.

 

[Old Navy]

I have found Lapua brass to be as much as .006 shorter than my new chamber. In that case I loaded them long the first time. The best die I own is a Harrell's.

 

[Ned Ludd]

As long as the chamber was cut such that the fire-formed brass only grew marginally (i.e. .001" to .002") that would work just fine. As has been noted above, in a chamber where the base-to-shoulder dimension grows by .004" to as much as .008", having a die made based on virgin brass dimensions would likely result in case head separation after a few firings. The question that might also arise is how "tight" can the chamber be and still function as intended? In a bolt action competition rifle where rounds are single-fed only, that might work just fine. In other circumstances, perhaps not so well.

 

[swd]

Because it’s easy to cut a chamber a bit oversize with a reamer and and the die fits the gun not the reamer so it doesn’t overwork the brass.

 

[Old Navy]

Just installed a new 6.5X284 barrel yesterday. Set up with less that .001" headspace. New Lapua was .0055 to .006" short. I loaded 142 SMKs over 48 grains H4350. They measure exactly what my foster go gauge measures now.