Once Fired Brass question

[Alucard]

Hey guys,

I have always heard that once fired brass will produce better groups then New brass. Is there any truth to that? If so, how much of a size difference in groups will there be from fire-formed brass compared to new brass? I always full length size my brass, I am not sure if that makes a differnece or not. Thanks for the info!

 

[Varmint Hunter]

"always" is a pretty encompassing word. I would be inclined to say "not always". /ubbthreads/images/graemlins/smile.gif

Typically, factory ammo or factory new brass is quite a bit undersized so that it will fit in any SAAMI chamber.

If comparing factory ammo or new brass with once fired, neck sized or properly full-length sized cases you may see a measurable difference. However, in an average factory hunting rifle, with groups running 1.5"moa, the accuracy may not be good enough to see any difference at all.

I have shot (previously fired)neck sized cases and full-length sized cases in the same rifle without seeing a difference in group size. If cases are properly full-length resized they will only be reduced in size enough to allow the bolt to close easily and no farther.

Another advantage to minimally resizing cases is the reduction in work stressing cases, thus extending case life. Extreme over sizing will cause headspace problems and case failures. /ubbthreads/images/graemlins/mad.gif

VH