Help with New 308 Upper/Bolt won;t close

[bmt]

This is almost certainly MY fault . . . .

BTW-This ain't my first rodeo, I have a carbine upper for this rifle and have run that upper for 5 years-- including 2 classes as Thunder Ranch Oregon.

I have a NEW DPMS 18" Bull Barrel Upper.

I shot 20 rounds through it with factory black hills ammo. No issues.

I cleaned it.

Now the bolt wont close completely.

The problem is slight, if I point the muzzle straight down and release the Bolt, it closes completely.

If the muzzle is pointed down range when I close the bolt, I have to push the bolt forward 1/4 inch to close it. It won't fire even if closed manually 1/2 the time.

Clearly, I de-greased something that needs grease. Its pretty "wet" now and the problems remains.

Any tips?

BMT

 

[country888]

Re: Help with New 308 Upper/Bolt won;t close

Humm... I would inspect BCG well. Gas rings, gas key, locking lugs ... Make sure they are not binding or burs. Im sure someone will chim in & some good advice!

 

[doc76251]

Re: Help with New 308 Upper/Bolt won;t close

I'd look at the gas tube in the upper and make sure it's straight. If it's not check you gas key on top of the carrier and make sure it didn't get "eaten" (you'll see a ring on the leading edge)

Swab out the bolt lug recesses you could have some crud in there.

Cheers,

Doc

 

[bmt]

Re: Help with New 308 Upper/Bolt won;t close

Thanks, will do.

BMT

 

[cwillits505]

Re: Help with New 308 Upper/Bolt won;t close

I'm gonna throw a wild one out there only because I've seen it before.. Guy brought me one awhile back with same exact issue, and same exact "after cleaning" problems.. I looked that thing up and down, bcg and all.. Nothing... No gas issues, no spring issues.. Low and behold it finally hit me.. Put a mirror in the chamber and he had left one of those tiny cleaning patches in the chamber area.. Was wrapped perfectly around the outside of the chamber area, so barely
Affected the bolt, and was really unnoticeable unless a looked for it specifically.. Just thought I'd put it out there..

 

[country888]

Re: Help with New 308 Upper/Bolt won;t close

Hey good call cwillits505! Wouldnt have thought of that!

 

[Ammo dog 2311]

Re: Help with New 308 Upper/Bolt won;t close

It mite help if you explain you cleaning procedures. Maybe it's something your doin while cleaning it. Did you check the buffer and spring ? Did you put the bolt back together right ? Did you bend the gas tube ? Is the charging Handel bent ? Just obvious questions not insults.

I would send it in and have dpms look at it. See what they say. My brother had a similar problem with his dpms and they changed the bolt carried, now he has no problem with it.

I have the dpms lr 308 and I am not happy. The upper and lower fit is terrible. The trigger sucks. The gas key is barley staked and I mean barley. Not top quality to say the least. Also my kar arms 1927 a-1 had a similar problem, I sent it in and after 2 months I got it back, the problem ? Needed a new bolt.

My guess is that you did nothing wrong it's a bad bcg.

 

[bmt]

Re: Help with New 308 Upper/Bolt won;t close

Remember: This rifle worked fine before I "cleaned" it.

I will go over it again and then post some answers.

Thanks

BMT

 

[smschulz]

Re: Help with New 308 Upper/Bolt won;t close

Pull out the BCG and see that the bolt moves freely.
I had one where the extractor pin was slipping out causing it not to move freely.
Replaced the pin and all was good.

 

[bmt]

Re: Help with New 308 Upper/Bolt won;t close

The bolt does NOT move freely. It feels stiff and "new".

BMT

 

[Travis S]

Re: Help with New 308 Upper/Bolt won;t close

Take it apiary again.wipe dry inspect lightly oil pay attention on reassembly.cycle bcg assy by hand to west down any sharp edges that may have come up. Also check your buffer and spring as well as the carrier for signs of the hammer dragging.

 

[bmt]

Re: Help with New 308 Upper/Bolt won;t close

Getting little time to work.

Switched out the cam--no change.

BMT

 

[bmt]

Re: Help with New 308 Upper/Bolt won;t close

I'm really starting to think that the gas rings are a touch oversized. . . . . . .

 

[Doug Shooter]

Re: Help with New 308 Upper/Bolt won;t close

Replace the gas rings they cheap. Sounds like they are causing the issue

 

[bmt]

Re: Help with New 308 Upper/Bolt won;t close

That's next. meeting the local "AR guy" (armorer/patent holder) tomorrow. Gonna put the "single ring" thingy in.

 

[bmt]

Re: Help with New 308 Upper/Bolt won;t close

Gas rings fine.

Barrel extension wear on bolt.

DPMS (by phone) and the Armorer and working on it.

BMT

 

[bmt]

Re: Help with New 308 Upper/Bolt won;t close

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: doc76251</div><div class="ubbcode-body">I'd look at the gas tube in the upper and make sure it's straight. If it's not check you gas key on top of the carrier and make sure it didn't get "eaten" (you'll see a ring on the leading edge)

Swab out the bolt lug recesses you could have some crud in there.

Cheers,

Doc </div></div>

WINNER.

Gas tube looked fine. The armorer swapped it out anyway (switch parts till its works strategy). Now it works. Just enough rubbing on the tube to slow the bolt down. Out of the gun and in the light, you can see where it was rubbing.

Thanks guys!

BMT