AR issue, help, idea's, anwsers please

[RWF]

what i call my race gun has started having rounds blow out there primers, this has been on a few different brands. it first started at a small match using 5.56 and gave me my first DNF. but did it again today at the range using PPU 223 match 75 grain.

the primers are not punctured at all the brass looks good just missing the primer.the primer just seems to fall out of the brass. it is a 16" mid length with a JP LMOS bolt carrier and adjustable gas block. it thought maybe it may need a new recoil spring i normally use a standard carbine lenth but this time i just put in the JP extra power. the only big thing i have done to it, is about a year ago i changed out the JP trigger "kit" for a Wilson TTU that i picked a the IDPA nationals at a good discounted price, i really do like it more than i thought i would.

this the same gun i have used at all over the south at matches.

any idea?

thanks

[Caster]

Interesting. I saw a semiauto Remington 30/06 do this once. It was excessive headspace. Strange thing is, it cycled perfectly and was pretty accurate. Go figure. Wouldn't hurt to throw a gauge in there.

[50 cal]

How many loadings on the brass? The primer pocket may be stretched.

May not be the rifle at all.

[RWF]

new black box federal 5.56, ppu 223 match 75, i do not reolad. as far as i know the 55 PMC and 62 grain PPU has never had it blow a primer that i know of.

[RWF]

Interesting. I saw a semiauto Remington 30/06 do this once. It was excessive headspace. Strange thing is, it cycled perfectly and was pretty accurate. Go figure. Wouldn't hurt to throw a gauge in there.

sounds like a plan i will get one order.

[50 cal]

Guess you need to check headspace then.

[RWF]

well i believe i found the problem, you could say it was headspace issue, some how my retaining nut that goes on the upper reciever became loose, not sure why, it would get some wobble in it. but i was going to try a new bolt when i noticed that the barrel was loose. i know my accuracy had dropped off, just thought it was me.

thanks

[RWF]

well it was not the barrel being loose, CMMG said for me to send them my complete upper and they will trouble shoot and repair even though it is only there barrel. they also sent me a return UPS label and will pay shipping each way.

i also talked to the folks at White Oak they explained that in the life of a barrel there is only one thing that will cause pressure to go up, and that is a build up in the throat. so scrub, JB bore compound, repeat.

be damn it worked, i guess i just got sloppy in my cleaning.

[Guest GunTroll]

JB is your buddy!