Gunsmithing DPMS 308 Ejector Roll Pin - 6.5 cm headspace

[cfulback32]

I have a DPMS 308 bolt, Krieger 6.5 cm barrel, and 6.5 cm go and no go headspace gauges. My problem is I can't seem to get the ejector roll pin out of the bolt. I have compressed the ejector, and that doesn't seem to help. I am using a Brownells #2 roll pin punch (5/32").

At this point it seems like the roll pin is either stuck or I am doing something wrong. My other option would be just relieving an area of the no go gauge for the ejector. I have already checked with the go gauge and it is fine with the ejector in the bolt.

Leaving the ejector in while checking the no go, I can't get the bolt to rotate into place, but since I'm fighting the ejector to try, I don't want to have a false positive and incorrectly think the no go gauge won't chamber.

Thoughts? Go ahead and relieve the no go gauge? It's only a $30 part and will still work just fine I think. Also to note, this is my first time checking headspace on any gun. Any advice is appreciated!

 

[bohem]

Re: DPMS 308 Ejector Roll Pin - 6.5 cm headspace

Measure up the bolt face, barrel extension and figure out your "Go" protrusion value, then drop the gauge into the chamber and see what the protrusion value measures. 6.5CM brass tends to be about 0.002" smaller than "Go" for reference.

With that all being said, you can take cigarette paper and add consecutive layers behind the "Go" to see when you can't get it to chamber up. If you're less than 0.003" you will be fine on that chambering and a piece of ZigZag is about 1/2 thousandth thick, so 6 plies of ZigZag

When you push on the ejector does it go flush or just past flush in the bolt head? If so, you don't have an issue.

 

[2156SMK]

Re: DPMS 308 Ejector Roll Pin - 6.5 cm headspace

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: bohem</div><div class="ubbcode-body">Measure up the bolt face, barrel extension and figure out your "Go" protrusion value, then drop the gauge into the chamber and see what the protrusion value measures.</div></div>

I'm guessing he does not have the ability to remove the barrel extension from the barrel in order to measure the boltface depth from the extension face if this is the first time he has ever checked headspace.

OP- Go ahead and clearance the no-go gauge.

 

[cfulback32]

Re: DPMS 308 Ejector Roll Pin - 6.5 cm headspace

Thank you for the advice guys. Randall, you are correct, I do not have the ability to remove the barrel extension from the barrel.

I ended up relieving the no go gauge and did confirm I had a headspace issue with my original bolt. I ordered up 3 more DPMS bolts from Brownells. They arrived today, and all 3 pass. They all can lock on the go and will not lock on the no go. I guess that my first bolt may have just been towards the end of the tolerance range.

From what I have read elsewhere, I will measure from the back of the lugs to the front of the bolt face, and go with the one that will result in the shortest headspace since all pass the go test (largest distance from rear of lugs to front of bolt face).

Thanks,
Andy