For those of you who dont already know, I have a Remington Model 700 ADL Synthetic in 300 Win Mag. No alterations have been done to the rifle beyond a trigger job of 40oz. I reload 180gr Nosler Partitions in front of 75.5 grs of RL22 and CCI 250 Mag Rifle Primers. The SAMMI over-all length for the 300 WM is 3.340", I had a tip from a guy on the G&A forum to load 180gr Nosler Partitions to 3.36". So I did, and everything has been going fine. Until now. I havent touched the depth guage on the bullet-press since Ive set it to 3.360", and I have shot about 100 of these reloads out of my rifle. We [my dad and I] just loaded up a round to see about only neck sizing instead of full-length resizing. Prepped one brass, primer, neck sized, charged with 75.5grs RL22, and seated the bullet. It measured 3.357" Is this change, no matter how small, something to worry about? Shouldnt the bullet-seating die be more accurate than that? Or is it more likely that it just got bumped?

.003" isn't enough to worry about for what you're doing. Like you say, the die could have been bumped and moved ever so slightly. You could also have a .003" "ding" in the bullet tip.

Yeah, thats what my dad figured, the whole ding in the bullet tip thing. This gives me an oppertunity to bring up another question; whats better, full-length resizing or just neck resizing?

It's more likely this. The bullet tip and the point at which the seating plug makes contact on the ogive can vary in length. The only ones I've seen that are consistant are the polymer tipped bullets.

It is not uncommon to be .003" over or under, that's why I get an average and make sure the longest fits in the mag and the others stay near the average. The point where the seater contacts the ogive and the point on the ogive that contacts the rifling will be much more consistant. If you use a bullet comparitor, such as Stony Points you will find this too.

Brent beat me to it. Bullet ogives vary enough -- especially if you changed lots after you set your die -- to make the OAL vary by this amount. It's not actually the OAL that matters so much (except in terms of fitting into the magazine), but rather the distance from the rifling leade to the full-diameter shank of the bullet.

My experience same as Brent & Stonecreek. If you're really interested, measure every round and analyse statistically, but if you're not close to the lands, that difference probably doesn't mean much. Good thing, because you're probably stuck with it!

If you are reloading for a hunting rifle my opinion is that you should full length resize. The reasoning is that you want this ammunition to function 100% of the time. If you only neck size you have a chance of finding that some of your ammunition will not chamber because of a dirty chamber or dirty brass. This would be frustrating if you were trying to shoot something. I also feel that you won�t give up much accuracy (if any) by full-length resizing verses neck sizing only. If you accept that comment then accuracy wise there is no reason to not full length resize. I think the only draw back to full length resizing is that you work your brass more. You will need to trim the case more often and the brass will wear out faster.

Ben

[ 11-07-2002, 21:58: Message edited by: Ben_Wazzu ]

I always full size my brass for big game hunting. It isn't worth the possible problem in the field. I have had some bullet seater dies that don't stay as "locked" when they are removed from the press. That can effect you OAL by just alittle with the movement ther also. I must agree that the stony point gauge is a great tool if you want to play with OAL. I like the bullet comparer option. Much more accurate readings since you are not using the bullet tip. Have fun

Hcliff