FL Sizing New Brass

[PALefty]

I full length sized some new brass for the first time. I attempted to follow some directions which I found online... to get a slight crush fit. However, no matter how far I screwed the die in, I never got any resistance when closing the bolt. Is this normal with new brass? Is it because the brass is so conservative with respect to SAAMI and factory chambers? Is there anything I can do to get a tighter fit... or will it require at least one firing to get bring the shoulder closer to the actual gun's dimensions?

 

[keithcatfish]

In my experience, new brass is a bit smaller than the SAAMI minimum headspace. When you full length resize new brass, the die won't touch the shoulder and body but will resize the neck. You have to fireform the brass first then adjust your die to bump the shoulder.

 

[mmcauliffe]

In my experience, new brass is a bit smaller than the SAAMI minimum headspace. When you full length resize new brass, the die won't touch the shoulder and body but will resize the neck. You have to fireform the brass first then adjust your die to bump the shoulder.

I have also experianced this with a bag of new Winchester brass. I ran them through my FL die with the neck bushing & expander ball primarily to get the neck back to round, many were "not so round". BTW - the die never touched the shoulder.

I remove the expander ball after doing this.

 

[PALefty]

Well, this confirms what I experienced. So at this point, fire forming/shooting is the only way I can bring the shoulder out.. correct?

Would it be pointless to attempt to find an accurate load with the first round of shots having the shoulder so far back?

 

[mmcauliffe]

Well, this confirms what I experienced. So at this point, fire forming/shooting is the only way I can bring the shoulder out.. correct?

Would it be pointless to attempt to find an accurate load with the first round of shots having the shoulder so far back?

I'll let someone else with more experiance answer but I will say...

Don't make the same mistake I did which was to load off the chart low...it's a waist of time, powder, bullets & didn't expand the brass enough. They actually grouped better than I expected but dropped like a brick. Luckily I only loaded 20 this way. The other 80 new casings I loaded with a normal load and have yet to shoot them. I'll use some as barrel warmers, the others I'll shoot them for group and see what happens, beats shooting them into the berm.

 

[billmo]

In some cases you might even have to fire the case more than once to get it blown out enough for the die to push the shoulders back. I just ran into that with my .223 AR-15 shooting the IMG brass. Bill