Home Forums Hunting & Shooting Ask The Gunwriters Mr. Barnsness; about sizing virgin brass

Not John, but an inexpensive method.

I use MEC bushings and a caliper. Takes 30 seconds to check. Put the fired brass and the bushing in the caliper, zero the caliper. Put a sized brass and the bushing in the caliper, read the caliper. Caliper reading is shoulder setback - in my case the caliper reads -0.002"

I centered the base of the brass against the sliding jaw. Centered the bushing on the fixed jaw. Supported the bushing/brass with fingers and slowly rotated them until they centered themselves - which you could feel. Ignored the reading until had the feel and checked the numbers.

Pictures show the fired brass.






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Con,

That's what I'm doing currently. Of course, I have no way to measure how much the shoulder is getting set back. Maybe it's one of those things I should call "good enough" and not worry about the rest...

mtnfisher,

Thanks for the post. What are the MEC bushings? Are these bushings for shotshell reloaders? That's the only MEC I'm familiar with...

Yep, MEC powder bushings.

So is the short - short version of the story - just use a neck sizer if you are using new brass

You can use a fired pistol case as a "bushing" for many centerfire rifle rounds.

A 40S&W works good for measuring a 30-06.

I had a machinist make up some bushings with various sized holes for the experessed purpose of checking shoulder set back, 1 - 2 thou seems about right for good case longivity. I size virgin brass to fit the rifles chamber, this rarely/never causes a shoulder set back. The die manufacturers recommendation of full length size, bumping over on the shell holder type size is bad advice and poor practice, unless it can be done with out shoulder set back, Redding makes + sized shell holders to accomplish this. Sizing to fit chamber does not do much if anything to the body but does make the case mouth round. Not an expert here but just think of the mechanics of what your doing and trying to achieve.

Not all that inexpensive at around $80+, but Larry Willis makes a great device for measuring shoulder set back. His company is Innovative Technologies. Check them out on line at http://www.larrywillis.com/

I have no stock in Larry's company, just like the products.

DF

I borrowed a fancy tool to measure it, and discovered that what I'd been doing was pretty spot on. I have other die sets where the adjustment is off the shellholder, but again I just sneak down until I get easy closing with a hint of feel at the bottom of the bolt stroke. I'm kind of glad I got to redirect $100 towards projectiles rather than a measuring tool.
Cheers...
Con

I have tried using the Hornady OAL bushings. I choose a caliber large enough to fit over the neck to about half way down the shoulder. Works for the smaller calibers but I do not have a bushings large enough for 7mm and up. Any one else tried this?

Yes I do!

.

That'll do but the RCBS Precision MIC is faster and easier, plus it gives you a readout in thousanths of an inch relative to the SAAMI specs for that cartridge. The downside is they are $50+ per caliber. As MD said, I've noticed a bit of shoulder-to datum line variation on even the most meticulously adjusted dies. I've found gas guns need a minmum of two-thousanths of "slop" to run and three is better.