RCBS precision MIC any good?
- Thread starter CSI-WALLEYE
- Start date
I have two precision MIC in .308 and .223, and I also have the Hornady cartridge case headspace gauge.
The precision MIC is calibre specific and only good for one calibre and the singe Hornady kit fits almost all calibers and is much cheaper.
The precision MIC is slightly slower to use than the Hornady gauge.
The Hornady gauge with a digital vernier caliper is easier to see and read.
Both gauges are comparators and not zeroed to a GO gauge or specific measurment.
My .308 precision MIC reads -003 or three marks past zero with a GO gauge in it and the .223 precision MIC reads -.006 with a GOprecision MIC gauge in it. Meaning a GO gauge is not zero on the precision MIC. The fact that the precision MIC is not zeroed to a GO Gauge was disappointing so it does not give actual headspace measurements.
I prefer the Hornady gauge for ease of use and speed if used with a digital vernier caliper. But this is because I'm 68 and have chronologically gifted eyesight.
The precision MIC may need to have the measurement lines touched up with a white grease pencil to see clearly.
Bottom line, if you have several rifles the Hornady gauge is more cost effective, but requires a vernier caliper.
Below a Colt 5.56 Field gauge at 1.4736
Below the Field gauge in a adjusted Hornady gauge, the gauge read minus .011 with the field gauge in it. And by placing a .011 feeler gauge between the two parts of the gauge it could be zeroed.
Below a factory loaded .308 cartridge in my precision MIC.
The precision MIC is calibre specific and only good for one calibre and the singe Hornady kit fits almost all calibers and is much cheaper.
The precision MIC is slightly slower to use than the Hornady gauge.
The Hornady gauge with a digital vernier caliper is easier to see and read.
Both gauges are comparators and not zeroed to a GO gauge or specific measurment.
My .308 precision MIC reads -003 or three marks past zero with a GO gauge in it and the .223 precision MIC reads -.006 with a GOprecision MIC gauge in it. Meaning a GO gauge is not zero on the precision MIC. The fact that the precision MIC is not zeroed to a GO Gauge was disappointing so it does not give actual headspace measurements.
I prefer the Hornady gauge for ease of use and speed if used with a digital vernier caliper. But this is because I'm 68 and have chronologically gifted eyesight.
The precision MIC may need to have the measurement lines touched up with a white grease pencil to see clearly.
Bottom line, if you have several rifles the Hornady gauge is more cost effective, but requires a vernier caliper.
Below a Colt 5.56 Field gauge at 1.4736
Below the Field gauge in a adjusted Hornady gauge, the gauge read minus .011 with the field gauge in it. And by placing a .011 feeler gauge between the two parts of the gauge it could be zeroed.
Below a factory loaded .308 cartridge in my precision MIC.
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Blastattack
CGN Ultra frequent flyer
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- Winnipeg MB
It seems like an incredible waste of money that achieves nothing. Who cares? Neck size, or minimum size and fire away.
In my case, i cannot agree.
I body size each firing before neck sizing, i want my 2 thou bump.
Big Ed
Happy to see i am not alone.
As in i was wondering in MIC was zeroed to go gauge, and was thinking mine wasn’t good.
Precision mic, .308, go gauge, -0.003”
I'd agree that a single- purpose tool like the PM (not a reference to our beloved Prime Minister.. nope) is a very limited tool to have.
I don't have the Hornady comparator either, all I use is a brass bushing exactly 1.000" long with one end bored to 0.400" to sit on the shoulder datum. I either zero a digital mic on the bushing, or subtract 1 inch from my dial mic measurement. Simple, always in calibration.. and cheap!
I don't have the Hornady comparator either, all I use is a brass bushing exactly 1.000" long with one end bored to 0.400" to sit on the shoulder datum. I either zero a digital mic on the bushing, or subtract 1 inch from my dial mic measurement. Simple, always in calibration.. and cheap!
Chambers and dies vary in size and checking the fired length of a case and setting your sizing die for minimum shoulder bump will extend case life. Meaning with using these gauges you help prevent case stretch and case head separations.
Having a headspace gauge just gives me a idea of the chambers actual headspace setting. And also how much the sizing die if adjusted per the dies instructions will push the case shoulder back. Example I have a Lee full length .223 die that can push the shoulder back .009 shorter than my GO gauge.
The old method of setting up the sizing die was to use feeler gauges between the die and shell holder. And keep using thinner feeler gauges until the bolt closed on the sized case without resistance. You could also use a black felt tip marker and color the base of the case and check for rub marks. I did this for over 25 years before buying the gauges to measure the fired and sized case length.
The gauges just save you the trial and error time of fitting the resized case to "your" chamber. And variations in brass hardness and the make of case can effect the case fit in the chamber. Meaning if you change brands of brass or use range pickup brass it is much simpler to measure the cases with a gauge, and not have to check the case fit in your chamber.
I besides using the shoulder measuring gauges I also use Redding competition shell holders that work like putting feeler gauges between the die and shell holder. You start with the plus .010 shell holder and work down to the plus .008, plus .006, plus .004 etc until the sized case reaches the desired case length. With these shell holders you never touch or adjust the die for shoulder bump. And you simply change the shell holder to get the correct case headspace length.
Example with buying bulk once fired military Lake City 5.56 cases I'm using the plus .004 shell holder when sizing these cases for .003 shoulder bump. And if I set the die up per the dies instructions with the die making hard contact with the shell holder I would have .007 shoulder bump and excessive sizing.
You can get by without gauges other than feeler gauges for up or down adjustment of the die and going by feel chambering a sized case using feel. But having the gauges is more accurate and saves time doing case chambering fit and bolt closing resistance closing the bolt.
The cartridge length tool is pretty hit and miss. I tried a couple of times, but I gave up on it.
Biged, in your picture of the PM, isn't that the bullet seating length cylinder, not the headspace measuring one??
Biged, in your picture of the PM, isn't that the bullet seating length cylinder, not the headspace measuring one??
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No it is the headspace gauge and you can measure a case or a loaded round. This is a reference for shoulder location of factory ammo vs your reloads and minimum shoulder bump.
Below is the head clearance between the rear of the case and the bolt face. This will also be the approximate shoulder bump distance, meaning .002 shoulder bump will be approximately .002 head clearance. This varies due to how much the case shoulder springs back after firing and your actual shoulder measurement.
Ok, I went and looked at mine and it is the headspace cylinder, I thought it was the bullet seater one.
Nobody here mentioned the bullet seating length function, with the sliding cartridge doo-dad. I really don't like it. I use the micrometer to measure seated rounds, but I figured out the throat length another way and use that length as a reference when seating bullets, and measure them with the micrometer function. That part I like.
Here's a pretty good review of the complete tool.
http://www.gunsumerreports.com/review_rcbs_precision_mic_308-win.php
Nobody here mentioned the bullet seating length function, with the sliding cartridge doo-dad. I really don't like it. I use the micrometer to measure seated rounds, but I figured out the throat length another way and use that length as a reference when seating bullets, and measure them with the micrometer function. That part I like.
Here's a pretty good review of the complete tool.
http://www.gunsumerreports.com/review_rcbs_precision_mic_308-win.php
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