Mysterious Malfunction

Talk about your guns and gear here
User avatar
creekerdoug
Member
Posts: 265
Joined: Sun Oct 18, 2009 10:40 pm
Location: WV

Post by creekerdoug » Sun Jan 23, 2011 3:35 pm

As always, thanks for the assist.

I've installed a O ring and it certainly does make the extractor way stiffer. The thing that puzzles me the most is why it ran for 30 flawless rounds, unsuppressed, on the first session and it hasn't run right since. I'll give you gents an update when I can get the thing back to the farm for some more testing.

User avatar
Hairy78
Posts: 735
Joined: Thu Sep 04, 2008 2:01 am
Location: Ashland, KY

Post by Hairy78 » Mon Jan 24, 2011 5:47 pm

The only reason I say it is undergassed is that a suppressor has no bearing on the extractor tension. If the bolt is moving too slow, double feeds can occur. I have had a 16" upper do this. I thought it was mags, until Magpuls would do the same thing. I checked my gas system and it was in spec. I had used a shitty BCG and saw some rub marks on it. After polishing the high spots, it has run flawlessly.

It could be extractor related, and the defender o-ring is always a good upgrade, but from my experience, my double feeds were caused by lack of bolt speed.
....................../´¯/)
....................,/¯../
.................../..../
............./´¯/'...'/´¯¯`·¸ F__ - Obama/Biden
........../'/.../..../......./¨¯\
........('(...´...´.... ¯~/'...')
.........\.................

User avatar
S Lance
Forum Administrator
Posts: 1141
Joined: Wed Sep 03, 2008 7:03 pm
Location: Russell, KY

Post by S Lance » Mon Jan 24, 2011 7:20 pm

I might speculate that the silencer can add to the dwell time of the system (just like having a 16" barrel vs. a 10.5" ) and therefore the extraction characteristics could be expected to change with the can off versus on.

This place has a pretty nice description of how the AR-15 operates:


http://www.ar15barrels.com/prod/operation.shtml



Having said all of that, I could be completely wrong.:cool:

User avatar
creekerdoug
Member
Posts: 265
Joined: Sun Oct 18, 2009 10:40 pm
Location: WV

Post by creekerdoug » Fri Feb 04, 2011 6:31 pm

I think I might have this thing whipped. I took the gas tube off, again, and instead if trying to clean the gas system manually, again, I used my compressor with a needle nozzle. I managed to get a very, very small piece of metallic slag to blow out of the gas block. I also installed the o-ring on the extractor.

I took it to the farm with about a 120 rounds of 5.56 surplus, .223 commerical and some of my .223 reloads spread across 4 different kinds of magazines.

I tried it first with the standard carbine buffer. It ran fine unsurpressed and would lock back on an empty magazine but the recoil was a little stout. I switched out the stardard buffer with the Spikes heavy buffer. It still ran fine, had better recoil characteristics, and it locked back on an empty magazine.

I put the suppressor on and it ran fine. I used up most of the rest of the ammo unsurpressed and, again, no problems. I'm pretty pleased and I appreciate the good advice you've given. Thanks.:)

User avatar
Gunworks
Posts: 726
Joined: Fri Sep 12, 2008 11:30 pm
Location: Ashland, Ky

Post by Gunworks » Sat Feb 05, 2011 11:33 pm

We aint that just dandy.

I finally get here and the problems solved.

My first thought was crud in the gas tube or it was under gassed.

User avatar
creekerdoug
Member
Posts: 265
Joined: Sun Oct 18, 2009 10:40 pm
Location: WV

Post by creekerdoug » Sun Feb 20, 2011 5:35 pm

I'm going to call this one a success. It if was going to soil itself it would have done so today at the match with an audience. It ran good. There was not a single bobble.

The only unanswered question is: What was my margin of victory over MRB?:D

User avatar
S Lance
Forum Administrator
Posts: 1141
Joined: Wed Sep 03, 2008 7:03 pm
Location: Russell, KY

Post by S Lance » Sun Feb 20, 2011 8:08 pm

creekerdoug wrote:I'm going to call this one a success. It if was going to soil itself it would have done so today at the match with an audience. It ran good. There was not a single bobble.
Very cool.

Post Reply

Who is online

Users browsing this forum: No registered users and 5 guests