Once fired brass.

[dead on]

Please tell me how important, as far as accuracy goes,is it to reload from brass that has been at least once from your rifle? Has anyone shot their pet load from both new cases and then cases that were fired from their rifle and compared groups?

[Big Z]

Unimportant. I only FL size..accuracy has never been troubled because the brass came from another rifle.

[spaniel]

If it is NEW brass, even FL sizing may not uniform the brass. It must be fireformed to the chamber to be consistent. I have documented that I get best accuracy from fireformed brass neck-sized vs new brass just neck-sized or FL sized.

If the brass was fired in a different rifle then FL sized, I'm not sure how much of a difference you will notice as the first firing should expand it out enough to be sized back uniformly by the die.

I prefer to match the brass to the gun and neck size only (for a bolt gun).

Up to 200 yards, no big deal. When you reach out to 500-800 yards, things start changing. With once fired brass in my gun, collet sized I can see std dev. go down to 10-15fps with large magnums and even less with varmit rounds. With new or mixed brass FL sized I can see std dev. up to 80fps. You start seeing egg shaped groups or vertical stringing long distance.

[thndrchiken]

Not enough to be worried about. Optimal would be fire formed and neck sized. but honestly, I have seen only minuscule improvement with neck sizing over full length sizing. That's just me, others may have different results.

[bronko22000]

Under normal hunting conditions - like BC said, you won't notice a difference. Off the bench at long range, probably.
But for hunting I will always use FL sized. I want those rounds to feed flawlessly if I need a quick second shot. A fireformed case may cause enough 'stickyness' to lose a chance at a second shot

[dead on]

Thank you, Rusty

[Frank in the Laurel]

Tha average off-the-shelf anything will never be able to tell, the slop in the neck, sometimes .006-9 per side cut by the factory these days will destroy everything elses affect/effect on accuracy. You need a custom cut chamber will tight tolerances before you need to worry about such things.. most of the off-the-shelfers today are lucky to be shooting inch or inch and half groups..after firing a shell or firing it on an empty chamber grab the bolt and see how much play there is..try it on a custom action and see the difference. I have found that if I size only about 1/3 of the neck, and let the cartridge swell to fill the chamber that I can really improve the accuracy but for big game hunting and cartridges it's just not needed and after all your shooting at a volleyball sized heart lung at least, I really don't care if it's shooting 2 inch groups as long as the action functions correctly that all that matters for the most part... good luck!

[Valentine]

if cases were only used once or twice.

[skb2706]

Originally Posted by dead on

Has anyone shot their pet load from both new cases and then cases that were fired from their rifle and compared groups?

Many many times. I shoot a ton of prairie dogs and we use up some brass. In general fireformed brass is more accurate for me. I only neck size unless I just have to shoulder bump them to chamber.