Why? 'broken extractor jp 308 enhanced bolt' at 350 rnds

[guidedmiscle]

Trying to figure this out. Luck of the draw bad extractor? Combination of the build/settings? I'm thinking I haven't done anything abusive.

Have shot 4 matches, did break in for barrel and sight in. Factory Privi Partizan 145 gr ammo, if I remember correctly they chronoed 2650-2700.

2nd match had a jam that occurred the last stage. Was a case that did not eject fully that was above a rnd that is being stripped from the mag. Wasn't sure what to think of it and did not give great consideration. In cleaning the rifle I did clean the gas system with pipe type cleaner first wetted lightly with hoppes the used dry.

3rd match 1rst stage was approx. 40 rnd stage, all good, 2nd stage about 25 rnds into it same jam, cleared it and continued. A few more rnds and same jam.

Before going to last match in thought might need more gas for greater reliability so open the Syrac gas block 2 notches. I had originally adjusted per instructions. Start closed, open in increments to were bolt strips rnd from mag give 2 more increments for reliability.

Last match 8rnds into it jam with case not extracted bolt has partially stripped rnd locked up at case not extracted. Pulled the bolt and carrier out wha la broken extractor.

The Barrel, Enhanced bolt were to be head spaced at JP. the Light carrier, Syrac adj gas block, captured spring and other JP parts all ordered and shipped together.

Thoughts/ideas appreciated

[sschultz]

One of the two JP LRP-07 that our sniper have had the problem. They had a bad batch call JP they will take care of you.

[Solidgun]

What is the upper receiver used and torque setting on the barrel nut?

[guidedmiscle]

Mega match set Upper and Lower receivers. Did recommended torque setting but at moment don't remember what it was. If I remember correctly there is a spread in inch pounds from such to such. Thinking is was closer to the higher end of the torque spread but is within spec. Friend has equipment/torque wrench that used. Is a 1911 manufacturer also Smith's other types Firearms including AR's

[3GunRunner]

One of the two JP LRP-07 that our sniper have had the problem. They had a bad batch call JP they will take care of you.

The underlined section above is the correct answer.

Edited December 10, 2014 by 3GunRunner

[co-exprs]

One of the two JP LRP-07 that our sniper have had the problem. They had a bad batch call JP they will take care of you.

The underlined section above is the correct answer.

+1 In the LR-308 platform the extractor is the weakest link to the entire system. JP has a new heavy duty extractor, but you must have gotten a bad one. The extractor in my 308 rifle now is the new JP unit and has 3500rds on it. Call JP and they will send you a replacement unit for sure.

[guidedmiscle]

thank you for the responses! I called JP as suggest and had planned on doing. they gave me some good feedback also in route to me is a new extractor.

Thank You JP for the great customer service and help!

Edited December 11, 2014 by guidedmiscle

[guidedmiscle]

new extractor received an installed. no time to test fire, first opportunity to shoot was a match. Yeah, not a hiccupfan great. the new extractor spring has an O ring around it and what looks to be a rubber insert inside of it. it's also laser engraved JP.

thanks again JP

[JBOT5000]

Just so you know DPMS is offering their gen ii extractors for purchase as a drop in unit. I put one in my dpms bolt with JP lightweight carrier and scs setup and it is doing the job so far I don't quite have 350 rounds through my platform yet so ymmv. Just a thought