From: cbl@uihepa.hep.uiuc.edu (Chris Luchini)
Newsgroups: rec.guns
Subject: Re: inside turning brass
Date: 22 Dec 92 18:45:44 GMT
Organization: High Energy Physics, University of Illinois, Urbana-Champaign

In article <1992Dec22.015822.18370@u.washington.edu>, toby@stein.u.washington.edu (Toby Bradshaw) writes:
#In article <BzMFsu.Fnx@news.cso.uiuc.edu> cbl@uihepa.hep.uiuc.edu (Chris Luchini) writes:
##I've got this barrel in a wild cat 6mm-284. My problem is that the
##neck thickness variation is 0.008-0.012.
#
#Are we talking just thickness variation or neck wall runout (out-of-
#round)?  If the necks are round, but vary in thickness, you can

	Both problems, mostly thickness variation.

#outside neck turn or inside neck ream.  Outside neck turning
#is preferred by benchresters for most purposes (I just turned
#60 necks for my 6PPC; every time I think about neck turning
#for a hunting rifle I remind myself how much I hate brass prep).
#If you have 8-12 thou runout, the brass is junk.  It happens, though.
#


	I do outside neck turn them, currently I turn them,
	expand to 30 cal, turn again, expand to 35 cal, turn again,
	and then in several stages neck to 6mm. the expansion
	and turning is needed, as the shoulder also has this large
	variation in thickness. 


##Precision shooting claims
##that thickness variation only gets worse as one gets closer to the
##case head. I've thought of necking the brass up to basic size (ie
##making it a straight cylinder) and then forcing it into a
##die, and then inside turning it to a consistant diameter all the way
##to the head. Does anyone do anything like this to match brass?
#
#Yes, the technical term is "masochist" :)
#

	Yes, I know. I've preped distroyed about 25 cases trying to
	find the minimal number of steps that needed to be done, and
	the above is it. I do _not_ want to have to do even as
	much as I currently do. 

#I bet it would be cheaper to find some good brass in the
#big 6mm of your choice and have your rifle rechambered for
#it than bore out existing cases and re-form them to 6/284.

	Unfortunatly, 6/284 is the bigist case that will work
	on a standard .470 case head size. I guess I could
	cut the belt off, and cut the head on magnum cases to
	.470, etc. . . ;(   [at this point it's not even funny]


	My gunsmith kept recommending a 6mmrem improved, and I kick
	myself every time I think about it. 

#You could take a ball mike to the local gun store and check
#out the 284 brass they have.

	I've done that. Every piece of brass I've checked at gun
	shows has the same problem.

	However someone on the net has offered to find me some
	good brass, as he has a friend with a 6/284 who doesn't
	have the same problem. I've heard that the brass factory loaded
	ammo has normal thickness variation. Are there any 284 shooters
	out there that would want to unload some of their once fired
	brass?

#  _Anything_ but what you
#have outlined would be cheaper.  I recently bought some
#..270 brass (happened to be Winchester) for my Dad's rifle
#and the worst case had less than .002 runout at the neck, and
#all the cases were within 2 grains of being the same weight.

	Weight variation on the stuff I have is +-~15 grains, 
	and the distrobution is very non-gaussian. ...
	I think I just have an exceptionally bad lot of brass.

#Commercial brass, at least some of it, is pretty damn good
#right off the shelf.  The Remington .308 benchrest case could
#be used for a checkweight on a balance if the stuff I looked
#at is any guide.  Makes me wonder why I pay $1 apiece for PPC brass.
#
##The implication in some of the articles/letters in the Best of...
##was that something like what I describe above is done.
#
#That makes benchrest machinists/shooters even crazier than
#the typical Usenet reader ... scary :)


	That's what I thought... 
*1110 W. Green/Urbana IL 61801/217-333-0505/cbl@uihepa.hep.uiuc.edu