Check Tools Before Measuring

[TropicalVibe]

Surprise, Surprise...

I want in on the Group Bolt buy, but a quick check of my bolt face depth reveled that mine is .141.

This is an AR Stoner type 2 18" barrel/bolt combo that I purchased a few years ago from Midway. For the most part, this barrel has been decent with aprox moa results. My brass does seem to stretch a little long when loading 28.2 gr 8208. I have also seen a case head seperation from 5x reloaded PPU brass. I didn't think muc of it, as there were many reports of issues with PPU. Because this barrel and bolt came as a matched set, I never used a go, no-go gauge. I think it's time to check this bolt.

Anyone else using this barrel/bolt combo? If so, have you measured your face depth?

Thoughts and advice are always appreciated.

TV

[Drillboss]

I have to ask, but are you zeroing the tail of your caliper against a flat surface before taking the measurement? I didn't the first time I tried this measurement, and I got some screwey numbers.

[LRRPF52]

Woah! What is your shoulder growth from unfired virgin brass to fired?

[TropicalVibe]

We have a winner!!!

Drillboss, I totally didn't think about zeroing the caliper to adjust for the tail. What do you know, my bolt face is exactly .136. Thank you very much!

LRRPF52, I will check the next lot that I shoot. For now, all my brass has been FL resized. I suspect, it will be fairly normal, now that Drillboss set me straight. Can you change the title of my post to "TropicalVibe bumped his head and forgot how to use his tools!"

Thanks again gents, I really thought my bolt was jacked up!

[Drillboss]

It's one of my guiding philosophies: See one, do one, teach one. You can pay it forward now.

I agree with 52's thought process too. I don't have headspace gages for the Grendel, but after I screw an upper together, I fire the first round from the hip, check that the bolt locked back, and then measure that case with Hornady's headspace comparator to see if it falls within the SAAMI spec range. Then I also know how far to bump back my cases for reloads for that barrel.