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mkoch78
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Posted: 7/6/2012 5:33:15 PM
Hi, just went to the range after some recent upgrades and had two double feeds in about 15 rounds. Because I just made a few changes to my AR I'm not sure where to start.

Problem:
Case not ejecting, causing a double feed. Upon inspection, the case was fully in the breech and could only be removed by shoving a cleaning rod down the front end of the barrel and forcing it out. Upon inspection of the casing, one side of the rim was ripped off (see pic), presumably by the extractor. Again, this identical problem happened twice in about 15 rounds shot.

Rifle:
S&W M&P15- Just changed the barrel and gas system from a 16 " carbine to a 14.5 mid-length from Ranier Arms with a pinned and welded Battlecomp 1.5 muzzle device. Barrel is Ranier's Cold Hammered Forged model.

Ammo:
Shooting BVAC .223 55 grain once fired brass. I was inclined to think it was the ammo but I've already fired 500 rounds before I made the barrel/ gas system change and never had this problem happen.

Potential Causes:
Ammo? Again, I fired off about 500 before the changes with no issues. Gas system? Barrel? BCG? I did check the extractor on the bolt and it appears to be functioning properly.

Thanks in advance for your help. I have a 2-day tactical carbine course in two weeks and would hate to be having problems like this or have my gun down altogether.

Dano523
Courses avec des cisaillements.
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Posted: 7/6/2012 6:44:46 PM
Either you did not take the time to break out a Chamber brush with CLP to fully clean out the storage grease and it's embedded debris from the the barrel before you when to fire it, or you have a gas problem going on.


When you went to first shoot the new barrel, did you install just a single round into a mag, charge and fire that single round with the empty mag still in the rifle to see if the rig was full stroking/ locking the bolt back on the bolt catch?????


If not, the go do that since we first need to know if the rig is at least full stroking or not.
Posted By PlaymoreMinds:

'Twas not the <cough> sweet and innocent <cough> PlaymoreMinds...

<---skips away in frilly skirts to Candyland, leaving gutters and snorkels FAR behind.
mkoch78
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Posted: 7/6/2012 7:06:06 PM
Thanks for the reply. Yes, first few shots were with just single round and bolt did lock back properly, no issue there.

I did not clean it first with a brush, but will do so now and hope that is it.

I've read on some other posts that some barrel chambers come in " tight " and need some breaking in.
Dano523
Courses avec des cisaillements.
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Posted: 7/6/2012 8:11:06 PM
[Last Edit: 7/6/2012 8:12:01 PM by Dano523]
Sounds like most of the problem is a dirty chamber, so cleaning that should help out a lot.

But still may be over gassed a tad (read op has already confirmed that the rifle is full stroking), so may want to add a #60 O-ring (about a dime at any hardware store) around the extractor spring to tension the extractor up a tad for break in.

If too tight of a head space was a problem, then you would have never gotten the bolt to lock back to begin with.


Also, you do have a lot post count, so let me state this, Hoppes is about the worst to use to clean and lube the auto loader. BreakfreeCLP can be used to not only lube the upper bearing areas/the gun, but to clean 99% of it as well. The barrel bore will need something a clean Copper out quickly, and here, something like Sweets solvent works great without having to do a lot of brush scrubbing.


So, B/C get pulled and a fresh shot of CLP to let sit while you are clean the rest,

Bore gets cleaned with Sweets first, then go after the chamber with CLP and a chamber brush, followed by running dry patches through the chamber and bore until they come out dry. Now go back to the B/C and the rest of the rifle to clean and relube those parts. As for lubing the upper bearing areas, wet the B/C inside and out, put it in the rifle still wet, then dry cycle the action a few times to migrate CLP off the B/C to the upper bearing areas. If in a few hundred rounds you state to have jamming problems again, pull the B/C, give it another coat inside and out, put it back in the action with a few dry cycles, and go on shooting.

CLP is not only a lube, but has a very good cleaning agent in it, and will dissolve the fouling before it has a change to build up and choke out the rig.
Posted By PlaymoreMinds:

'Twas not the <cough> sweet and innocent <cough> PlaymoreMinds...

<---skips away in frilly skirts to Candyland, leaving gutters and snorkels FAR behind.
sully
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Posted: 7/7/2012 12:28:47 AM
The stuck casing could be caused by many things like maintenance, ammunition, and timing issues. Have you tried the rifle with any other types of ammunition? Clean the chamber thoroughly as already mentioned. Have you changed out anything like the stock, action spring (buffer spring), buffer, bolt or bolt carrier?


CY6
Greg Sullivan "Sully"
SLR15 Rifles
TheDefensiveEdge.com
(763) 712-0123
mkoch78
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Posted: 7/7/2012 9:58:41 AM
Thoroughly cleaned chamber with brush and CLP, bought two new types of ammo and will go back to the range today to test. Will report back when done.
Have not changed anything else like BCG, buffer or spring.
Thanks
mkoch78
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Posted: 7/7/2012 8:27:31 PM
Update, went to range today and fired 60 rounds. 20 Remington 55gr , 20 Remington 45 gr JHP, and 20 BVAC once fired brass.

Fired 59 rounds with all casing ejected, and the LAST ONE got stuck in the chamber, failure to eject, just like the last ones.

Starting to think its a combination of tight chamber and soft brass on the BVAC ammo.
ezlife45
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Posted: 7/7/2012 10:54:05 PM
Scrub the chamber very well. Polishing may get you want you want. YMMV
mkoch78
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Posted: 7/8/2012 7:34:05 PM
Scrubbed and polished chamber really well and NO more failure to eject! Shot about 60 rounds of various types of ammo at the range today and no more ripped case rims!

I am drawing the conclusion that the new barrel just needed the chamber to be broken in through a mix of polishing and just running a few hundred rounds through it.

Thanks all for the help.