Prepping new brass question

[gcoulsey]

I'm starting to prep some new Lapua brass ready for next week when I collect my new rifle,
I have sorted 200 cases into 2 piles by neck wall thickness.
+- .0005" and everything else.
(the 'everything else' pile has nothing more than .001" variation)

about 70% of the cases are in pile 1, so far this lapua is pretty impressive.

I've taken 50 cases out of pile 2, to use for load development, I have neck sized them, uniformed pp, deburred flshole and chamfered mouths.

So I'm now thinking this brass is pretty sweet, and about ready to prime, and I thought I would just quickly spin a couple to see what the neck runout looked like, and to my horror, out of 5 random cases they ranged from .005 to .010" off centre!!!
Is there anything I should have done/can do differently to minimise this? Should I have FL sized them instead of necking them?

Or is this just normal variance that I need to segregate and discard the bad ones??
Bearing in mind these are for load development, but even so.. Am I worrying too much at such an early stage??

(redding Big boss, and redding dies used)

thanks, giles

 

[Victor N TN]

Re: Prepping new brass question

Don't cry about them until they have been fired at least once in the rifle. New brass is known to drift after basic forming.

Unless you are shooting benchrest or long range (600 to 1000 yards) .001" in neck wall thickness isn't going to mean anything.

 

[Dogtown]

Re: Prepping new brass question

Concentricity issues at the neck are pretty common in virgin brass, especially larger magnum calibers. It's really just the result of brass banging around in transit from the factory, to the dealer and eventually to you.

For .223 and .308 I rarely bothered doing anything about the necks unless they were grossly out of alignment upon visual inspection. For .338LM and .408CT I would always neck size them first as I had a particular bushing diameter I preferred for each. This combined with an in-line seating die resolved any runnout issues I had with the magnums.

 

[gcoulsey]

Re: Prepping new brass question

ok, so its best to ignore them, and go ahead with priming/powder/seating?

i just didnt know how much effect it would have on my load testing @100 200 yrds. if its negligible, then thats fine, i wont cull any cases yet.

thanks!

 

[clmayfield]

Re: Prepping new brass question

You are getting a little better numbers as I am (about 20% below .0005")... and I agree with the above. Fire-form and then see what happens with concentricity. You can cull from there, but not before.

 

[bowshot]

Re: Prepping new brass question

I had the exact same experience w/Nosler brass with my .204 Ruger. Everything was fine (100% under 0.0015 TIR) after 1st firing.

For me, Nolser brass, Lee collet neck sizer, Wilson seater yielded bullet TIR (case side of the olgive) < 0.0015" 43/50 cases, after both 1st and 2nd firing. Not sure what is the cause of the 7 above that...

 

[gcoulsey]

Re: Prepping new brass question

Great, thanks chaps, just need to decide on where I'm going to start on my loads now, I have a box of 155scenars, and 168 smk's to start with, (175 smk out of stock)
I'm itching to load up the cases, but half inclined to wait till next weekend and I pick the rifle up to take all the measurements off..
Or do just load up to saami specs to start shooting as soon as the scopes mounted??!!!

I'm so damn impatient lol!!

 

[Victor N TN]

Re: Prepping new brass question

Giles,

You didn't list a caliber. But if you are shooting a standard 308 Win I would suggest the standard length of 2.800" OAL. If you have a custom tube & chamber you MIGHT gain a little from adjusting the length. MOST factory rifles are chambered so deep you really don't gain that much.

You didn't list a powder either. But most powder companies have web sites that has a great deal of data for almost every load.

If you have other questions, let us know. Beware of ANYONE that KNOWS IT ALL.

 

[gcoulsey]

Re: Prepping new brass question

Ha! Yep sorry, I didn't want to stray off my original topic onto load data,
but yes, it's my first .308win
a blue printed remmy action,
26" 1-10 twist A&b barrel
riflebasix trigger
AICS stock
20 moa base.

I want to use varget, as I have been using that to great success for several years now on my 22-250, and like the idea of just buying/using one powder.
It's my first custom build too, so very excited to get behind the trigger!!