epoletna
Well-Known Member
Please keep us informed what you find out and what you decide.
Headspace question for new Carbon6 prefit barrel
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Did you send them dummy rounds to cut to and did you use new Adg brass when you did?
cohunt
Well-Known Member
He said it was a pre-fit
I did not send them dummy rounds and it was supposedly cut to SAAMI specs
I've heard more than one person say a comparator is a poor messing tool. So what is a good tool to use for measuring shoulder datum and/or seating depth?
Do you have depth mic's to pull us a few measurements?
I do not. I only have basic tools and do not consider myself any sort of gunsmith. This is my first forte into building anything custom or semi-custom myself. My gunsmith is about 4weeks out on being able to take a look at it so I was trying to learn and figure it out on my own. I appreciate all the responses and feedback as I've learned a bunch on this forum (and probably spent way more in the classifieds than I should have
)!!MagnumManiac
Well-Known Member
I have made my own, but Larry Willis at Innovative makes one for most datum sizes.
The problem with a comparator is the radius left on the edges of the hole and if you run a bore gauge into them, they're not exactly what they say they are.
Other than what I made for myself, the best measuring tool that is easily sourced is the RCBS Precision Mic, very accurate to .001"and I have never found a bad one.
I have also found bad go gauges in the past, not common, but sent them back.
Comparators are only good for comparing fired and sized case datum measurements, but measuring headspace, nope!
Cheers.
I guess I'm not following on how to mic a shoulder datum? At least not with some other tool needed?
MagnumManiac
Well-Known Member
My point is in regard to using a comparator tool to measure a go gauge. Each headspace datum is at a particular diameter, .375" for 30-06, .420" for belted mags and WSM/RUM etc.
A RCBS Precision Mic is the most accurate measuring device on the market, it has precise graduations and you can easily see .0001" if you use them often enough. It will even measure go/no go gauges accurately.
Cheers.
I would not be concerned at this point. If the headspace was too long then yes I would not want that. If you can resize your cases sufficiently then no issue going forward.
ntsqd
Well-Known Member
Since I wasn't familiar with the RCBS tool I looked it up. I can see how it would be the ideal tool for this sort of measuring. Unfortunately I don't see the .30 RSAUM listed. They can likely make one, but it'll be a special order.
Interested in what the results of removing the ejector does for testing with the no/no-go gauges.
Interested in what the results of removing the ejector does for testing with the no/no-go gauges.
Sometimes the ejector does not snap around the case head of the gage as easily as it does with a brass case so just make sure the case head of the gage is behind the extractor.
FullCurl8
Well-Known Member
That's not what an Ejector does. Proper headspace gauge use can never occur with the Ejector in place if it's a spring loaded bolt face plunger style ejector. And Extractors sometimes make contact as well, but with less frequency. But removing both from the bolt will ensure your feeling everything there is to feel.
