bullet runout

[kraky]

Most bullet runnout is caused by pulling the case over the expander ball in your die. When the expander isn't centered in the middle of the die it will pull it off center. Below is what I copy to forums when this topic comes up. I had a friend try this tuning a week ago and he wound up getting less runnout than with his fancy Redding Bushing dies! Here is the info:

My $.02 worth---ALL dies with expander balls need tuning. Think about it...a piece of typing paper is .003" thick--what are the odds that the expander is not PERFECTLY centered in a die and could pull a case slightly off center??? Pretty good I'd say. Pull the expander stem out of the die (and now is a good time to clean the inside of the die). Run about 5 brass into the die and see if they come out concentric. If they do (and usually they will) you now have to try and get that stem centered on re-assembly. A great way that helps is to put a piece of very concentric brass up into the die to hold the stem in place as you tighten it down. Sometimes this takes 2 people unless you have 3 or 4 hands. AFter reassembly try sizing some brass and check runnout. If not good then do very small turns of the expander stem--probably 1/32 of a turn at a time. Resize some brass and repeat the small turns. At some point I can almost guarantee that you will get GREAT RUNNOUT CONSISTANTLY. (Somehow, someway the expander spindle will hit almost perfect centering in the die body) I have many dies that consistantly make less than .002" runnout after sizing with most of the brass at .001" and less. I own, hornady, redding, forester, rcbs, and lee dies. ALL OF THEM HAVE BEEN TUNED and most make fantastic ammo and all make good ammo!! I have never ever got a set of dies from any factory that made as good of ammo as those that I have done this simple work with.

[AJ Peacock]

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Achieving .000-.005" run out is near impossible and is not needed, especially in a hunting cartridge.

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Gene,
Did you mean .000 - .0005"? As .005" is easy to achieve with good brass and procedures. I reloaded 35 rounds for my 7RM this weekend, only 3 rounds were more than .002", They were around .0035". Most of the others were around .001-.0015" runout with several being less than .001". Measurements were taken 1/4" back from the tip on the loaded round using a Sinclair Concentricity gauge.

BUT, this is with GOOD Brass (Norma in this case). With mixed brass that has large neck thickness variations, I've seen typical .007-,008" runouts. In my opinion, it comes down to #1 starting with good brass #2 good procedures to not mess it up.

Don

[wapiti13]

My Bersin tool fits 308 and 6.5/284 & 284 Win. Anyone interested, post a reply or send me an email.

[CPerkins]

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My Bersin tool fits 308 and 6.5/284 & 284 Win. Anyone interested, post a reply or send me an email.

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Please send me some details.