Do you REALLY NEED to full length resize new brass? I have heard yes, and no?? 300RUM brand new Remington brass........ Shouldn't it come from Remington already the right size? With the mouth already tensioned and all?? I have measured all of them, and no trimming is required, just want to save the hassle of FL resizing a thousand cases..........
thx
jordan

Depends on how anal you are. Since all of your cartridge values change once they have been fired, I only bump the resizing ball thru each neck to make sure they're round and then load 'em up and shoot 'em. If you're using boat tail bullets, I doubt that you even need to do that unless a neck is really out of round.
Then I trim to length, etc, etc. This also negates the need for deburring the inside of the flash hole that so many folks angst about.
Range pick up or 1x brass that isn't from your rifle needs to be F/L resized b4 its first firing.

I don't know why anyone would want to do so.When I first read about it here on AR,it took me a while to understand what they were talking about.I shoot my new cases as they are and could not imagine any benefit from necksizing beforehand.

I resize new brass to round up the case mouths beat up in handling and shipping. It actualy doesn't resize the case to speak of. If the case mouths are round, I load them up.

Thanks guys........that is what I was thinking too........but, I asked the same question a month ago about NEW .44MAG brass, and the general consensus was definitely to resize first.....so, I'm glad I asked again.........

No resizing for me then, as long as they will chamber in the rifle with no issues out of the box before I put powder in them......I'll check that first obviously......

thx
Jordan

I think that neck sizing is a must for new brass. Necks on many new cases are all banged up, so sizing necks only is required.

quote:

Originally posted by DMB:
I think that neck sizing is a must for new brass. Necks on many new cases are all banged up, so sizing necks only is required.

Agree, and I always trim to length. Factory u/p brass seems to be very inconsistent in that regard.

Sometimes the trimmer just spins, other times it cuts a lot of neck length.

I only fl size after firing max loads,if using light loads i neck size only as long as it will fit in chamber,all of my hunting loads get chambered before i use for hunting.

quote:

Originally posted by captjordan:
Thanks guys........that is what I was thinking too........but, I asked the same question a month ago about NEW .44MAG brass, and the general consensus was definitely to resize first.....so, I'm glad I asked again.........

No resizing for me then, as long as they will chamber in the rifle with no issues out of the box before I put powder in them......I'll check that first obviously......

thx
Jordan

I found that bulk straight wall pistol brass can need sizing to get good neck tension. I loaded about 50 new 500 Linebaugh cases a few months ago and crimped very hard. Still, the necks were loose and the W296 just didn't want to light off. I had to pull the remaining 30 or so and start all over. I can't recall the same issue wth rifle brass; just out of round mouths.

I love a lyman "m" die....plunge the brass over it just to get the mouth diameter consistant.....chamfer the mouth and load....AFTER THE FIRST FIRING...is where I start my more careful case prep.

I ALWAYS resize new brass, trim and chamfer the mouths. The resizing operation doesn't take long and then you're assured it's gonna chamber. I think it's silly not to.
Bear in Fairbanks

I hit new rifle brass with a collet neck sizer, but thats all. I wait for all the other prep until after initial firing.

Link to Bart Bobbit 1994 post about new brass

Bart was a long time competitor at Camp Pendleton.
He is a great one for posting his accuracy technique quantifications.

quote:

Originally posted by michael.tx:
I hit new rifle brass with a collet neck sizer, but thats all. I wait for all the other prep until after initial firing.

Same here.

I'm buying Nosler Brass now and it comes very well sized with a drilled and chamfered primer pocket and neck, weights are less than .5 gn different across 50 cases. I look at it this way: The first firing is to fireform anyway. why work the case if it fits? In magazine guns, cases get crimped so neck tension is not an issue. If the Case fits, no need to FL resize

My $0.02

I also reround the neck,check length and trim if needed, then chamfer, load and shoot

quote:

Do you REALLY NEED to full length resize new brass? I have heard yes, and no??

Why do that? It would only assure that the necks and shoulders are consistant.

When I start with new brass I make sure the neck is round by champhering inside and out, load and fire. After the first firing I full length resize, measure and trim if necessary, load and shoot. Normaly I get two or three firings before trimming. Been doing it this way for years and shoot 3000 plus or minus rounds per year with chamberings from .243 to 50 BMG. Good shooting.