Blown primers

[praveen]

You said you have a reamer. Use it, by hand, to cut out the carbon.

Ha.. I tried that... didn't make a difference at all ! That's why I wasn't sure it was a carbon ring but I'm going to try all the suggestions and to confirm that the barrel/chamber is the issue, I'm going to put a new barrel on it and try. If all goes well with the new barrel, I'll know the old barrel/chamber is the issue. If not, then there's something else.

 

[ridgeway]

Fire control issues. Ignition is the one of the biggest things guys write off as not an issue. Till it is an issue.

 

[bozo699]

Ha.. I tried that... didn't make a difference at all ! That's why I wasn't sure it was a carbon ring but I'm going to try all the suggestions and to confirm that the barrel/chamber is the issue, I'm going to put a new barrel on it and try. If all goes well with the new barrel, I'll know the old barrel/chamber is the issue. If not, then there's something else.

Praveen,
Your barrel isn’t why you’re blowing primers, with what you explained it’s a carbon ring, if you’re using 400 primers,…. In conjunction with a carbon ring is the perfect recipe for what you’re seeing. Do as Bill Norris suggested or JB works good too and your problem will go away I’m sure of it.
P.S
If you really like your reamer don’t try to remove carbon with it, you will dull it or chip it or both.
Wayne

 

[butchlambert]

Your chamber might be oversize at the web. Measure your fired brass at the .200 line.

 

[mgdietrich]

Check your neck clearance. I bet the ISSF chamber with Lapua brass is right on the limit of minimal neck clearance. New lot of brass, different lot and you could be tight. Can you take a fired case and a bullet slides in with no interference?

 

[gunsandgunsmithing]

I have a hawkeye... and looked through it.
I suppose one could call what I saw as a carbon ring.. but I'm not too sure of it. It looked maybe 1/16" wide.
Still, that would explain the issue.

If you have a junk bbl or a stub of some sort, ya might test your planned process on it before doing it on your good bbl, and check it with your hawkeye. Might save your butt.

 

[gunsandgunsmithing]

You said you have a reamer. Use it, by hand, to cut out the carbon.

This actually works great but scares some people. Nothing to be scared up with just a modicum of attention to not jack it up. Very simple and easy. If he tried this, can't see how he would still have any carbon ring left. I'd look elsewhere.

 

[Mastershot]

Ok, I have a gun that was shooting great for 500 rounds. I changed brass to alpha dasher brass and I was blowing primers every shot. Turns out the firing pin is the issue, after 50 rounds of blowing primers the firing pin is now too long.

 

[K22]

Would appreciate if you post the results of cleaning the throat for the "carbon ring" relative to it solving your problem of loose primer pockets.

Thanks in advance.

 

[praveen]

So, last night I kinda went medieval on the throat area with a nylon brush and first with C4 and then again with Iosso.
Shot some loads today and lo ! No blown primers and the velocities have come back to earth to what they should’ve been ( about 120 fps lower).
Thanks all for confirming and reconfirming the carbon ring. Looks like a more thorough cleaning regiment is required for this rifle.
Thanks again. You may have saved my next match.

-Praveen

 

[Bill Norris]

So, last night I kinda went medieval on the throat area with a nylon brush and first with C4 and then again with Iosso.
Shot some loads today and lo ! No blown primers and the velocities have come back to earth to what they should’ve been ( about 120 fps lower).
Thanks all for confirming and reconfirming the carbon ring. Looks like a more thorough cleaning regiment is required for this rifle.
Thanks again. You may have saved my next match.

-Praveen

Happy to help. Go win the next one. LOL.

 

[bozo699]

Happy to help. Go win the next one. LOL.

^^^^^^^^This
Wayne