RCBS Precision MIC

[GrimmRoper]

I just got my new RCBS Precision MIC and I am not very happy with it at all. If you have one, please let me know what I am doing wrong.

I have a Savage 10 FCP, which is a tack driving son of a gun. I am going from just measuring OAL to trying to be as precise as I can. I followed the instructions on how to get my bullet seating depth. I placed the freebore tool into the body and used the land nut to read out.300. I tightened the screw very tight.

Then I placed the freebore tool into my chamber and shut the bolt on it slowly and carefully. The bolt would not extract the tool, so I barely had to tap the tool with a rod as per the directions and got it out. The readings I got after I placed it back into the body and land nut were negative (to the left of the 0). In fact, the body and land nut bottomed out on the threads before touching the tool.

I placed a loaded round of federal GMM in the tool and came out with a postive number on the body and land nut. I shoot .344 moa with the Federal ammo with this gun. What can I do to get this to read properly?

Thanks,
Nate

 

[mdmp5]

Re: RCBS Precision MIC

The freebore tool is a complete pain in the ass. It slips and slides and even when I did get mine to work, it measured my lands .04 closer than they actually are. I confirmed my true measurement with the Sinclair tool. If you want to keep it, don't use the freebore anymore. Use a brass case and a bullet, then use the mic to gauge the measurement. Remember that the mic doesn't give true measurements; it is just an indicator for comparison.

 

[ALASKAPREDATOR]

Re: RCBS Precision MIC

It's a pain in the ass to use on the Savage's. I have 2 guns and 2 Mic's-.308 and .223. The key to getting a good consistent reading is to insure the freebore tool is locked into the bolt face prior to insertion into the chamber. This is done with your third hand; one to hold the rifle, one to hold the bolt ready to close, and one to lock the freebore tool into the extractor. Seriously, I seem to remember last time I used a set of pencil thin long nose pliers to manipulate the freebore tool underneath the extractor to lock in, then carefully close the bolt making sure the freebore tool goes directly into the chamber. I did it 10 times then used the average. Have fun!!

 

[USFTR]

Re: RCBS Precision MIC

I also quit using the RCBS freebore tool and switched to the Sinclair. The Sinclair model works MUCH better! With a little patience, you can make multiple measurements with a range of about 0.002". Just make sure the main stem in the unit is as centered as possible. It uses a fired case and the bullet you want to use for proper fit to your chamber.

 

[EddieNFL]

Re: RCBS Precision MIC

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">I also quit using the RCBS freebore tool and switched to the Sinclair.</div></div>

Ditto. The case mic works well for measuring shoulder bump.

 

[btm_54]

Re: RCBS Precision MIC

I had one they suck. I could not get repeatable measurements. I ended up with a Hornady one which works every time.

 

[MitchAlsup]

Re: RCBS Precision MIC

How to use the RCBS Freebore tool:
A) throw it away
B) have a cold one -- that was hard work!

How to use the RCBS to measure freebore/where are the lands
A) take a case and size between 1/3rd and 1/2 of the neck
B) seat a bullet in the unpowdered unprimed case 0.2" longer than expected OAL
C) carefully insert cartrige in chamber
D) carefully and slowly close the bolt
E) carefully open the bolt
F) carefully bring the bolt back a little bit
G) stick you finger in the extraction port and prevent the ejection spring from riding the case along the edge of the chamber
H) remove cartrige with lands-seated bullet
I) measure the ojive position with the RCBS ogive turret
J) repeat at least 3 times or until 3 successive reading are within 0.002 of each other.
K) measure OAL
L) write both ojive and OAL numbers down

 

[Fuzzball]

Re: RCBS Precision MIC

The RCBS Mic case shoulder and OAL devices are great. The "free bore" tool is not.

I also have a Sinclair and a Hornady tool. I've gone back to the old "marks on a cleaning rod" method; simplier and quite accurate even tho it's not "high tech." Most sporter rifles shoot best some 20 to 50 thou (or even more) off the rifling so high precision in OAL to the lands really isn't of much help in the final analysis.

 

[targaflorio]

Re: RCBS Precision MIC

John Feamster has a good chapter on gas gun reloading in: Precision Shooting Reloading Guide [Spiral-bound]
Dave Brennan (Editor)
He is a fan of the Precision Mic and includes some tips.

 

[targaflorio]

Re: RCBS Precision MIC

What is the Sinclair tool you are referring to?