do i have to resize brand new brass
 

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

RE: do i have to resize brand new brass
 

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.

RE: do i have to resize brand new brass
 

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.

RE: do i have to resize brand new brass
 

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

RE: do i have to resize brand new brass
 

I always resize new brass.

RE: do i have to resize brand new brass
 

I do too

RE: do i have to resize brand new brass
 

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[:@]

RE: do i have to resize brand new brass
 

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.

RE: do i have to resize brand new brass
 

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.

RE: do i have to resize brand new brass
 

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.