texhookem

Do you have to resize brand new brass? If it makes any difference I am using winchester brass.

Gundigest

I do, because I have rolled the neck in when seating the bullet. I think this has done done it to me a few times. I resize new brass to be safe.

Jeff Ovington

I do as well.I back the die seveal turns away from the shell holder as not to
set the shoulder back and run the expander ball through the mouth of the case.

handloader1

I also just make sure the case mouth is round, but do not resize the case. Good luck.

stubblejumper

I always resize new brass.

HighDesertWolf

I do too

Briman

Yes.
I tried to cut corners once and primed 100 new cases only to find out while charging powder, that 1/2 of them had necks that were out-of-round[:@]

Solitary Man

Lapua (maybe RWS too) is pretty much the only brass I've used that didn't require sizing before using it for the first time.

mossy33oak

yes this is what i do also, many of my new brass i get, have horrible necks on them. this process of turning the sizing die up a turn or two is called partial full length?? I believe thats what bigcountry told me.

bigcountry

If you don't resize at least the cheaper brass like remington and winchester, the necks are very tight and when you seat the bullet, this can knock you neck out and cause the copper to peel if not deburred real good.