68 replies to this topic

[bar-d]

Any of you AR builders/shooters ever run into extraction issues on a carbine AR? I am still trying to work out the problem with my build. It will not extract the fired case. Everything I have researched points to overgassing, causing rapid bolt function, not allowing the cartridge time to return to normal size. The bolt functions before the pressure has dropped in the barrel because the distance from the gas vent to the bolt is so short on the 16" barrel. Even with an upgraded extractor spring and o-ring, same problem. I have a suspicion the buffer spring that came in my collapsible stock set was a middy or rifle spring. I have ordered a Wolff Extra Power Carbine spring and H buffer.
Hopefully, this will slow the cycle time and allow enough dwell time to function correctly this time. Any thoughts?

[youngdon]

Try ar.com or one of the websites that deal exclusively in AR info.

[knapper]

The carbine type have a smaller gas port than the longer barrels so they must work with loads that are higher pressure than the rifle ones do. I have seen a gas tube that will circle around the barrel and give more time for the gas pressure to travel around the tube and get to the action. I haven't shot many loads that were not other than mil-spec 55 gr. and some are 62 gr. That is what I have read, or seen on videos. Some times I have some cases that do not have the pressure to bring the bolt to hold it open, this is while target shooting in a match rifle.

[ebbs]

Not sure if youngdon meant http://www.ar15.com or if there's another site similar to it. You may have checked there already. LOTS of resources and guys who have had the same problem you have before. I've never heard of it repeatedly like that. You basically have got a really fancy single shot, huh? Maybe you should post it in the Single Shot thread.

[youngdon]

That sucks bar-d who did you get that upper from?

[Chris Miller]

youngdon said:

That sucks bar-d who did you get that upper from?

Yea! But more importantly, where did your perfect lower come from??

[ebbs]

youngdon said:

That sucks bar-d who did you get that upper from?

If I remember right that's the one he got from Rguns.com.

[bar-d]

ebbs said:

Not sure if youngdon meant http://www.ar15.com or if there's another site similar to it. You may have checked there already. LOTS of resources and guys who have had the same problem you have before. I've never heard of it repeatedly like that. You basically have got a really fancy single shot, huh? Maybe you should post it in the Single Shot thread.

A very expensive single shot.

[bar-d]

ebbs said:

If I remember right that's the one he got from Rguns.com.

Yup, from Rguns. I sent the complete upper back and they "checked it out" and it worked fine for them. They said they shot it and it functioned just fine.

[bar-d]

Chris Miller said:

Yea! But more importantly, where did your perfect lower come from??

Got if from Super C's Firearms Emporium. Excellent customer service. Limited inventory but was able to score 2 Spike's Tactical lowers before they relocated.

[wvcoyote]

bar-d, I know people having had problems similar to what is happening to you . What caused thier problem was not properly lubing the bolt carrier group.
couple of ideals to try, lulubricating the whole bolt carrier assembly, also after chambering a round tapping your forward assist to make sure your bolt is fully forward and locked.
hopethese ideals help.

[wvcoyote]

 5-27-2010 8;15;58 P&.jpg   87.04K   18 downloads this what I was talking about
 5-27-2010 10;00;25 &.jpg   90.12K   14 downloads

[bar-d]

wvcoyote said:

bar-d, I know people having had problems similar to what is happening to you . What caused thier problem was not properly lubing the bolt carrier group.
couple of ideals to try, lulubricating the whole bolt carrier assembly, also after chambering a round tapping your forward assist to make sure your bolt is fully forward and locked.
hopethese ideals help.

Nope, that ain't it. Cleaned, lubed, checked gas seal alignment, the whole 9 yards. The bcg has been cleaned and lubed 6 times in shooting the 25 rounds I have fired through it. The bolt and extractor seats properly, even tried the forward assist, but the ejector scrapes the side of the rim, pulling off brass shavings.

Edited by bar-d, 27 May 2010 - 07:33 PM.

[headhunter25]

Stupid question but are your gas rings on the bolt lined up? They don't need to be. For sure it won't cycle then. That's weird, it functioned fine at the factory but won't shoot worth a [Excuse my language.... I have a limited vocabulary] back home. Has to be something simple.

Chris C.

[bar-d]

headhunter25 said:

Stupid question but are your gas rings on the bolt lined up? They don't need to be. For sure it won't cycle then. That's weird, it functioned fine at the factory but won't shoot worth a [Excuse my language.... I have a limited vocabulary] back home. Has to be something simple.

Chris C.

Check the alignment to make sure they are staggered every time I clean and lube the bcg. I have no idea what kind of lower they mounted it on to test fire it. More than likely it was a carbine spring and heavy buffer. As I posted earlier, I suspect the spring in the stock I put on it is a rifle spring. Thanks.

[ebbs]

Chris C., even something simple like maybe they sold him a lemon? Never know, if tolerances aren't up to par it could very easily function as a whole and fire the round okay, but not allowing something small like the extractor to pull the spent casing out. When bar-d first posted about his upper he got from Rguns I remember Chris M. saying something about hearing negative feedback on the Rguns stuff.

They've been saying all along that it fired okay for them, but haven't given him any kind of proof. Bar-d had to go through all kinds of hoops to get them to have a look at the BCG, then even to get it back from them, then had to have the whole upper sent in. Doesn't seem like much of a standup operation to me.

Edited by ebbs, 27 May 2010 - 08:10 PM.

[bar-d]

Trying to get any info out of them was like pulling teeth. I got no explanation, written, spoken or otherwise about what they did to "check it out". Just, "it worked fine for me". That is why I have no idea what the real problem with it is and am having to try one thing at a time to try to fix the problem myself. Frustrating
Good price or not, I will never buy anything else from them. It is not worth the hassle to save $50.

[ebbs]

Had a factory defect on a gun I bought new one time. It was my first Thompson Center Encore I ever bought, the 50 cal Pro Hunter muzzleloader. Anyway, took it to the range when I still just had open sights on it and couldn't figure out why my point of impact was landing 6" left at 50 yards no matter how much I adjusted the rear windage. Moved to 100 yards and it was a foot left. A good 'ole hunting buddy of mine was standing behind me and insisted I have a look at the barrel from the bore to the frame. IT WAS CURVED!

Apparently after production it somehow randomly missed the laser barrel straightening device and left boxed up in pitiful condition. You could take that barrel off the frame and lay it on a flat surface and there was nearly 1/16" of a gap between the table and the middle of the barrel. I was sick, but TC received the gun quickly, was easy to communicate with, and all in all I had it back within 2 weeks of the day I had it sent in for repair. The point I'm trying to make is, they sent me a range report along with the order sheet to show where it had been and what was wrong with it then what they did to fix it. Along with the range report I received the paper target they used to show it's accuracy dead center at 50 yards and the windage on the rear site had returned to "zero."

A good gunmaker/seller/dealer is going to issue proof of some sort of what they did, how they fixed it, and proof of testing it for safety and effectiveness. It doesn't appear that Rguns has done any of those things to back themselves up or give you piece of mind.

Love that barrel. Took several whitetails with it since then and can ring a gong at 250 yards over and over. Once I got over everyone giving me crap about shooting deer around corners and trees with my gun that curved bullets, I was a happy camper.

[headhunter25]

Question Bar-D.... Are you shooting factory ammo or reloads?? Reason I ask I have been down this road before. Also is the spent round stuck in the chamber, having to get it out with a cleaning rod. Could be that when they reamed the chamber the reamer was close to being out of speck. Hense making for a tight chamber. A couple of thousands could make a difference.

Plus what's Rguns?? Remington?? Another idea is if you have a friend that has an AR also put your upper on his lower and see what happends.

Chris C.

Edited by headhunter25, 27 May 2010 - 09:24 PM.

[bar-d]

headhunter25 said:

Question Bar-D.... Are you shooting factory ammo or reloads?? Reason I ask I have been down this road before. Also is the spent round stuck in the chamber, having to get it out with a cleaning rod. Could be that when they reamed the chamber the reamer was close to being out of speck. Hense making for a tight chamber. A couple of thousands could make a difference.

Plus what's Rguns?? Remington?? Another idea is if you have a friend that has an AR also put your upper on his lower and see what happends.

Chris C.

Federal factory 50 gr. hp. The case is not stuck. When it fires the extractor is engaged but slips off the rim. Since I can only shoot one round from the mag at a time, the bolt stays open after the shot. Hit the bolt release, bolt closes, and manually eject with charging handle every time. I think the case it still expanded and because of the carbine length, the bolt goes back before the pressure has time to clear the barrel letting the case return to normal size. The Wolff Extra Power spring and H buffer I ordered should at least tell me if I am on the right track.