Anyone use RCBS Precision Mics

Discussion in 'Reloading' started by fireroad, Jun 26, 2009.

  1. fireroad

    fireroad Well-Known Member

    Messages:
    308
    Joined:
    Apr 22, 2009
    Anyone every use RCBS Precision Mics? Did you find them a useful tool to help shrink groups and dial in loads...or where they a waste of money? Seems like they would be useful with Berger VLDs.
     
  2. boomtube

    boomtube Well-Known Member

    Messages:
    1,595
    Joined:
    Oct 8, 2007
    Well, at least I do, several of them, and want one more. Not sure what you mean about "dialing" in loads, etc. tho. The Mics just give me info, how well I use that data isn't a direct reflection of the potential value of any such measuring tool itself. Guess they are about as helpful with one type of bullet as another. ??
     
    Last edited: Jun 26, 2009

  3. fireroad

    fireroad Well-Known Member

    Messages:
    308
    Joined:
    Apr 22, 2009
    Sorry, what I meant by "dialing in" is figuring out exactly how far of the lands you are, measuring ogive, etc. Have you compared the RCBS to the old Stoney point/new Hornady guages?
     
  4. boomtube

    boomtube Well-Known Member

    Messages:
    1,595
    Joined:
    Oct 8, 2007
    Ah, I see, okay.

    Well, first step is finding the distance between the lands and bolt face. The RCBS kit provides what they call a "free bore tool" for checking max OAL from the bolt to the lands off the bullets ogive. For controlled feed rifles it works fairly well but, IMHO, it's no good at all for push feed rifles so I don't use that part at all.

    I also have the Stoney Point max OAL and case measurement tools but don't really like them as well so I've reverted to the old way to find the max OAL. That's to close the bolton an empty chamber and run a cleaning rod (I actually use a wood dowel rod) until it hits the bolt face and lightly cut it, squarely, at the muzzle with a small knife blade. Then I remove the bolt and put the bullet I want to try into the throat, holding it lightly against the lands using a pencil as a "ram rod". Insert and mark the rod again at the muzzle. Using a dial caliper, I measure from knife mark to mark. It's quick, easy, cheap and plenty accurate for what is needed because I NEVER find best accuracy at or in the lands for factory rifles. Thus, it just becomes a reference point for seating tests, not a specific measurement correct within a thousant.

    I seat THAT reference bullet into a dummy case to precisely match the OAL I just measured for it. Then THAT dummy round goes into the die box and gets used as a transfer gage for all further work with THAT bullet. After I measure it on the ogive with the Case Mic seating thimble, my test rounds are seated back in .005" steps, as gaged by the Mic, until I find the best shooting depth for that type of bullet.

    The Mic is also great for rapidly checking shoulder length on fired and then resized cases. Using the fired shoulder length as a reference, just set the sizer so the shoulder gets moved back an average of .002". That much provides for an easy fit and long case life with very little stretching. Understand that brass sprimg-back at the shoulder will vary a little so we can't get it exactly the same on each case, we must use a workable average setback or go nuts diddling with the sizer!

    So, for case measurements and seating depth gages, both the Stoney Point and RCBS Mic tools actually work fine. As you can tell, I (slightly) prefer the RCBS Mic tools over my Stoney Point tools. The RCBS length measurment thimble-tools are totally consistant between loading sessions and using them leaves my dial caliper free for other measurements.

    On the other hand, I think RCBS charges much more for the Case Mics than can be justified (as is usual for RCBS). So, if I had to start over at today's prices I'd likely stick with the Hornady/Stoney Point or the simular style Sinclair tools and be comfortable with them too.
     
    Last edited: Jun 27, 2009
  5. fireroad

    fireroad Well-Known Member

    Messages:
    308
    Joined:
    Apr 22, 2009
    Boomtube - Thanks for the great explanation. It sounds like if I use your dowel method (already went out a bought some) that the only use the RCBS would have is measuring ogive (case mic seating thimble) and checking shoulder length ... is that correct? If so, I could just buy Hornady LNL Bullet Comparator for measuring the seating depth of loaded ammunition from the bullet ogive. Do I need a device to measure shoulder length if I'm neck resing only with a Lee collet die? Again, thanks for the insight.
     
    Last edited: Jun 28, 2009
  6. boomtube

    boomtube Well-Known Member

    Messages:
    1,595
    Joined:
    Oct 8, 2007
    "the only use the RCBS would have is measuring ogive (case mic seating thimble) and checking shoulder length ... is that correct?"

    It is for me anyway. And, while I REALLY LIKE THAT case thimble PART, the current cost is too high for what little it does. The Hornady LnL tools are a bit more clumsy to me but they work and are a lot less costly, especially if you have several cartridges to work with.

    I'm fortunate in that I bought my four Mics cheap enough on eBay before foolish bid prices on used equipment begain to exceed retail. And lucky to have a great small metal lathe in my garage too; I have made steel "pads" to drop in the bottom of a 30-06 Mic to bush it for a .308/7-08/.260/.243 but the bullet seating thimble won't be usable on the other diameter bullets (so I use the LnL type tool for them). Of course the basic 30-06 model works for .270 and can be also be used on a .280. My .300 Win Mag Mic works for the 7 mag as well. My .223 Mic has pads for measureing .222 and .221. My .22-250 Mic is padded to work on my 6mm International. So, I get a lot of milage out of a few Mics.

    What I'm saying is that one Case Mic CAN serve for multipule cases when you need them to. But, the LnL tool is still the better deal by price at this time. IMHO.
     
    Last edited: Jun 28, 2009
  7. fireroad

    fireroad Well-Known Member

    Messages:
    308
    Joined:
    Apr 22, 2009
    I shoot 243, 280, and 300WSM so I'm looking at 3 mics. At $40 a pop, that gets real pricey real quick. The lnl basic bullet comparator set comes with all the bushings I need for those calibers for $35, but only measures oal from the ogive. I guess I'll start there and keep an eye out for some used mics.
     
  8. Limbic

    Limbic Well-Known Member

    Messages:
    320
    Joined:
    Jun 26, 2008
    I use the mic to help partial full length resize. It helps me find my headspace off of the shoulder. I really like the hornady COL and bullet comparator. It helps really nail down the COL and find out how long the round will be before it touches the lands.
     
  9. fireroad

    fireroad Well-Known Member

    Messages:
    308
    Joined:
    Apr 22, 2009
    The COAL tool you are refering to is old Stoney Point guage that requires the modified cases, correct?
     
  10. Limbic

    Limbic Well-Known Member

    Messages:
    320
    Joined:
    Jun 26, 2008
  11. boomtube

    boomtube Well-Known Member

    Messages:
    1,595
    Joined:
    Oct 8, 2007
    "The COAL tool you are refering to is old Stoney Point guage that requires the modified cases, correct?"

    If you refer to me, yes. BUT - I really don't care for that method of finding the lands any better than the crop-failure RCBS Freebore Tool so I DON'T use the modified cases. I believe the marked cleaning rod/dowel trick is faster, easier and actually more accurate for finding the lands..

    The old Stoney Point/new LnL case length tools (that is, head-to-shoulder) is quite good for setting a FL die properly. So is the caliber specific bullet ogive bushing they use to measure and then adjust the head-to-ogive length of a cartridge after the lands are found with the dowel. The only downer with any such tool is that we have to be careful not to let it get loose on the caliper jaws or readings will be inconsistant.
     
  12. fireroad

    fireroad Well-Known Member

    Messages:
    308
    Joined:
    Apr 22, 2009
    Boomtube - Yes, COAL tool question was for you. That is the one I planned on skipping on and using the dowel method instead.

    As for the case length tool, is this this the one you are refering to...

    MidwayUSA - Hornady Lock-N-Load Bullet Comparator Basic Set with 6 Inserts

    or this one...

    MidwayUSA - Hornady Lock-N-Load Headspace Gage 5 Bushing Set with Comparator

    or get both?
     
  13. Limbic

    Limbic Well-Known Member

    Messages:
    320
    Joined:
    Jun 26, 2008
    They measure two seperate things. The comparator measures C.O.A.L off of the ogive. The bushing set measures brass size. The datum line is not always on the shoulder technically but I don't guess that matters when you are trying to get your brass to exactally fit the chamber. I guess the bushing set can take the place of the precision MIC
     
  14. larrywillis

    larrywillis Well-Known Member

    Messages:
    192
    Joined:
    Mar 18, 2002
    Consider this ...

    Our Digital Headspace Gauge does the job of all the different size of Precision Mics ever made. It measures the shoulder clearance that YOUR handloads will have in YOUR particular chamber, and it works on every caliber from 22 Hornet to the 378 Weatherby.

    [​IMG]

    Even better than the Precision Mic, our Digital Headspace Gauge can also display the distance from YOUR bullet ogive to the rifling in YOUR particular chamber. It does this after locating your ideal OAL using a simple tool like this:

    [​IMG]

    It takes into consideration the exact bullet you're using, and our Digital Headspace Gauge compares this to your handloads. Visit our website at WWW.LARRYWILLIS.COM and check it out.

    - Innovative