It is really necessary to full length resize new brass for belted cartridges? Here is my rationale for saying no:

1.Headspacing is not a problem (it spaces off the belt).

2. It fits in the chamber of my gun as is (single shot--easy to check)

3. If I full length resize the brass, I am only making it smaller in most dimensions, thus increasing the slop in the chamber and the amount the brass must expand to fit the chamber upon initial firing.

Why would I do this? What am I missing here?

Thanks in advance.

KYNADOG,
Welcome to the site. I dont think your missing a thing. I full length size new cases to insure they are the correct dimensions. But one thing that I do is to adjust my dies to form cases to the headspace of my rifle beforehand. I really see no problem with sizing with a neck sizing die to insure the necks are ok. You didn't mention which cartridge you're loading for. On belted cases I like to headspace the cases as if they were a rimless case and headspace on the shoulder. Just my way of doing things. I hope that this is of some help. Good luck.

[ 08-30-2002, 06:25: Message edited by: BigBob ]

kynadog,in 243win, i take new bulk brass, check to see if brass will chamber in rifle. So far brass always ok. If the mouth is dented, i bump the mouth with the expander button to make it round.Load and fire. 243winxb.

I try to use the same system of reloading every time I sit at the bench. This includes new brass. It may seem redundant but the repetition ensures that I don't miss some other operation which could be critical.

kynadog, I just size the case neck for about 1/4th of its' length to make the bullet pull uniform. Then I trim for uniform length, chamfer the mouths, load and shoot!!

get yourself a lyman "m" die. they are about $10 and they iron out wrinkles in new brass like nothing else. To me, new brass seems to have "catchy edges" at the case mouth and since you have to get the case mouth "round" before chamfering I hate to run them into a normal die--to me it seems to sometimes be "catchy" on the expander button and they pull off center. The lyman "m" die doesn't do this cause it just a caliber specific mandrel. I love mine and can tell you a quick size with the m die and a quick inside chamfer of the case mouth and you are ready to load ammo with very very consistant neck tension and usually very good concentricity.

IIRC to set the die for headspacing on the shoulder on a belted round, it has to be "fireformed" before.

So it seems the solution is to round the necks ( expander ball or M die ) , load up, fireform, and then carefully adjust the die.

Good shooting! Hermann

I don't usually full-length size brass at all; I generally shoot a case the first time at a range and partial- or neck-size after that.

I must be in the minority here as l full-length resize all new brass. I guess l just don't trust that all cases regardless of brand will be concentric (sp?) to begin with. I then fireform them usually with full power loads and once this is done l only neck size until the brass has been loaded a few times and starts to require some pressure to chamber. The other case preparation to new brass is uniforming primer pocket and flash holes, trimming to a uniform length depending on the length of the chamber, deburr and chamfer case mouths. Varmint and big game hunting loads are treated the same way.

Good luck

I full length resize all the time.