Anyone Use RCBS Precision Mic?

[sfonelson]

So I have been reloading for several months now. I have shot hundreds of rounds through my M1 Garand and two AR's with no issues at all. I have also worked up loads for each specific rifle.

I have debated on whether or not to get the RCBS precision Mics for reloading. What's the real benefit? Does anybody here use them? I know they are on the list from Randall on what reloading equipment to purchase, but I haven't found the need for one yet.

Any thoughts?

[Ahhnother8]

It will allow you to measure the brass length after it is fired in your rifle. Then you can set your sizing die to either "bump" the shoulder back .001" or not at all. Your brass will last longer because you don't size it down .006"+- to fit in any chamber out there, then when it is fired it stretches back to fit tight in your chamber, then repeat until case head separation.

Necessary - no
Handy - yes

[sfonelson]

Sounds like something I would only be really interested in when getting into precision shooting. Right now I am just looking for good accuracy with my handloads.

Thanks for the info!

[Vicious_138]

When sizing for auto-loading (AR) you need to do a full length size, not just a neck size.

Neck sizing only would be for your specific bolt action rifle.

[sfonelson]

When sizing for auto-loading (AR) you need to do a full length size, not just a neck size.

Neck sizing only would be for your specific bolt action rifle.

? Not quite sure where this post came from.

I already FL size all my brass for all my semi's.

[killshot44]

Without measuring fired brass, you don't know how where to set the die to optimally set the shoulder back. You're obviously sizing down enough (since they chamber) but could be setting them back way too much, causing the brass to be excessively worked, which leads to splits in the neck and work-hardened brass (which make neck tension uneven; poor accuracy). Usually .002/.003" of set-back gives me the best results, YMMV. But if you're setting yours back .007"+ you won't get as much life out of those cases.

RCBS Precision Mics are okay, I bought/used one when I started, but $50 for every caliber? I now use the headspace gauge bushings from Hornady with my calipers to measure fired cases and my set-back. You can use the "body" that holds the bushing with their Bullet Comparator bushings, too. For measuring OAL from the datum of the ogive, sorting bullets by length etc.