6br brass runout after sizing ????

coyote

coyote

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My 6br f-class gun shoots great with straight bullets once I fireform them there is no runout when I run them through my bushing neck die they come out with about 3 to 7 thou runout on the necks.

My friend offered to use his wilson bushing die and the results are the same I have been reloading for many years and have never encountered this problem,maybe one of you guys have seen this before.
 
What are you doing after your first firing? Are you full length sizing or partial neck sizing?
If you are inside neck sizing on your first time maybe the inside sizer is pulling on the neck. I think I'd try just sizing the outside and pull the inside sizer part off the die. The Wilson die only partial neck sizes but seeing you're getting the same problem I think I'd rule out a die problem but I'd maybe switch the bushings between the two dies and see what happens. I'd also try sizing about half way down the neck then turning the brass half a turn then size the rest of it and see if you're still getting runout. Did you use two different presses when you switched dies? I'm assuming your buddy has an arbor press with his Wilson dies and your's is threaded so if you used two presses that shouldn't be the problem. My guess would be that something is going on (if you are inside neck sizing) but that may be a shot in the dark.
 
@coyote in our discussion at the range on Saturday you indicated that this is in a no-turn chamber, and so the neck expands about ten thou on firing. Also, you were neck sizing in one step (one bushing used to go from fired neck diameter to ready-to-load diameter)

Did you get a chance to try sizing it in two steps, to see if that improved things?

It does sound pretty mysterious I have to say
 
I have a 6BR with a no-turn neck. It comes out of the chamber, fired, with Zero runout.
I load my ammo with a Wilson straight line neck sizer and seater. I am surprised if runout exceeds .001" on this ammo, loaded with the 105 Berger VLD.
Something is going on there, for sure. I would never accept that much runout, even if loading hunting ammo.
If you are using an expander button, I would get rid of it and try again.
Also, do not size your brass any more than is needed to hold the bullet firmly (C .0015" max)
Regards Eagleye.
 
I am using a bushing hand die like a wilson no expander ball, I ran my brass through a full length die for the first firing there was no runout once fireformed.

Daniel I tried it in 2 steps and I still had runout it was not quite 10 thou but rather 4 or 5 I dont know how I came up with 10 I think it was the wind lol.

The chamber is a 272 neck and loaded is around .2695 I was using a .267 bushing ,I took the expander ball out of my fl die a while ago and ran a case in it when it came out it was .259 :eek:.
I think what has happened is the brass has become work hardened.

After annealing a few case necks this afternoon some that had little runout to begin with I ran them through the bushing die with a 267 bushing no runout but to much tension .
The next few I used a .268 bushing and it seems good :D.
 
Well I just got done annealing the rest of the brass and sizing them again in my neck bushing die, I had to go to a .268 bushing from a .267 to get the correct tension.

None of them have more than 1 thou runout even the ones that went in with a lot of runout came out straight,it seems that work hardened brass will not size up true.
The fl die I used to size with on my initial firing hardened the brass quite a bit to the point where it must have been springy or something.

This is the first time I have had brass do this ,my 22br started cracking necks last year before I annealed it but never would it size up with runout.
 
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