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Cjnut

LR .308 Bolt sticking and wont cycle

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Wondering if someone in here has run into this problem: I have a newly built DPMS LR .308, 20 in. barrel, Nickle boron BCG, running JP enterprise silent capture buffer, & Odin works adjustable gas block...I cannot get it to cycle, in-fact every shot, the bolt sticks hard forward and its a knuckle buster extracting the round. I've ran the adjustment screw on every click from full in to full out on the gas block...even to the point the screw shot out the front (hopefully I can get a replacement from Odin). I put a non adjustable block on, and exactly the same problem. Triple checked the gas block was aligned correctly. I'm stumped. Once I get the spent round out, the bolt slides like silk. I can chamber a round and extract it smoothly. But once I send a round down range, it jambs up. I removed the upper and looked at the bolt from the underside as it was stuck and it almost looks like the bolt is twisting/sticking behind the feed ramp teeth? Any help would be much appreciated!

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10 minutes ago, Ravenworks said:

How much oil.is on the bolt?

New bolts need to be WET

Carrier, lots of lube on the bolt carrier. I'm pretty sure that's what he meant ^^^

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Had it pretty wet with CLP, then went back out and lubed it up with grease. I'll try soaking it in mobile 1 overnight and try it again in the a.m. Thanks bud for the quick help. I'll post the results in the morning. Hope it works

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What does the brass look like after you get it out of the chamber? A lot of folks have problems w/the JP recoil set up. Was the bolt properly headspaced?

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Used another of my .308 lowers with standard spring and buffer that cycles great, also used the others bolt...just to weed out possibilities. same problem regardless of configuration. Brass looks fine other than some straight scratch lines down the neck. Although, it looks as though the case expansion line is a little higher on the case. Have not gaged headspace, I plan to buy the gages if I cant solve the problem. Upper was purchased complete through Moriarti Armaments.

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Sounds like the chamber may be a little tight. You may have to get it reamed out a little if the problem doesn't correct itself with break-in as more rounds are thrown down range.

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Problem solved. Gas port was drilled .073 for 16" car....I have 20" rifle. Drilled it to .094 and cycles perfect. Moriarti claims to fire all uppers prior to shipping, but now we know. Cycling problem would have been obvious had they.....

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52 minutes ago, masonb55 said:

Having the same issue. I'm not sure the diameter of my gas port but I'll see if your solution can fix my problem!

No, do not drill anything yet. Check your post first

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If. If you are running reloads by chance loading using rcbs dies mine was not fully chambering fully and when using the forward assist it would be sticky while ejecting. The base was not getting fully resized evenvwith th cam over while resizing. Had a small base redding body die ran all through it no more issue. Now it is at about 350-400 rounds so i checked my gas port on the barrel for a 20" barrel. It was .087 approx.  Used a #42 .0935 all cycling issues have gone away. Still keeping bolt dripping. May or may not help good luck.

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14 hours ago, Richardmac48 said:

If. If you are running reloads by chance loading using rcbs dies mine was not fully chambering fully and when using the forward assist it would be sticky while ejecting. The base was not getting fully resized evenvwith th cam over while resizing. Had a small base redding body die ran all through it no more issue. Now it is at about 350-400 rounds so i checked my gas port on the barrel for a 20" barrel. It was .087 approx.  Used a #42 .0935 all cycling issues have gone away. Still keeping bolt dripping. May or may not help good luck.

Gas port was too small.  Not uncommon these days, with barrel manufacturers on every street corner.  There's a vast many of them that don't know what they're doing, and shouldn't be in the gas-gun barrel business.

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