Problem with AR...

[EBWhite]

So this weekend I put together a lower and slapped an upper on it.

It is a Lauer lower, dpms parts kit, dpms 24" midway special and a ACE full length stock. Everything went together good in the lower but after loading the mag, pulling the charging handle back, the bolt did not go all the way forward. I tried to fire it and nothing happened.
So i proceed to remove the rear pin and it wouldnt let me seperate the lower and upper. So i got the front pin out and then i was able to seperate them.

The recoil buffer and spring were touching the back of the hammer and the little pin and spring by the threads where the buffer tube is where pushed out of place.

Any ideas what happened?

[bu-bye]

You may need to move the stock into the receiver a little bit more so the buffer retaining pin sits lower. I'm not sure how the ACE stock works but if they are like the tele stocks you might want to give it one more turn and see if it will make it all the way around without pushing the pin. A pic of this area would help a lot too.

[D.T. Rouland]

Sounds like the stock wasn't threaded in far enough.

[EBWhite]

Does anyone know if the ace fx full length stock requires the use of the small flat plate that goes between the stock and the lower? (i was not using it)

I had the ext. tube screwed in pretty far but it seems the spring and buffer tube put too much pressure on pin and made it push forward and out of the hole.

[EvolutionGSR]

I use the ACE full length stock, and do not use the plate. Everything worked out fine. Its on a Stag.

[five.five-six]

could it be a head space problem?

[ohsmily]

could it be a head space problem?

HUH???? I am not sure you know what "headspace" is if you think that a headspace issue caused this problem.

[DV8]

You want to check that the buffer tube is screwed in far enough to catch the buffer retaining pin but not too far where you cant close the upper. A proper full length tube will screw in right on the money all the time.

If you can see that its screwed in enough make sure the tube is torqued down properly. The tube on my Colt M16 lower was only hand tight when I first got it and what happened to you happened to me. My incident was worse though as the buffer retaining pin took a chunk of the receiver (the hole where it sits) with it when it let go. Luckily, there was still enough of the hole that it could still function. I was using the same stock that you have by the way...

[five.five-six]

HUH???? I am not sure you know what "headspace" is if you think that a headspace issue caused this problem.

well one of us does not, basicly if the go gauge fails, it will do exactly what is described. personaly I will not be the first to fire a bolt / upper that has not had the "head space" checked

[docsmileyface]

I had the same problem, you didn't twist the buffer tube enough time, or you didn't tighten the stock you put on good enough (not familiar with the ACE or whatever you used).

I took my OLL to Vegas, unpinned her, then attempted to take her virginity with a USGI 30 rounder. First two shots worked like a dream, then the bolt refused to go all the way forward. After trying a failed attempt at SPORTS I put her on safe and opened her up and the buffer retainer had came out because I didn't have the stock tightened in properly.

Luckily the guy at the Gunstore (Discount Firearms) just got back from an AR armorer class and fixed it for me free of charge. My AR works like a dream. But I'm willing to bet your problem is the exact same problem I was running into.

[TonyM]

well one of us does not, basicly if the go gauge fails, it will do exactly what is described. personaly I will not be the first to fire a bolt / upper that has not had the "head space" checked

An incorrect headspace will not remove the buffer retainer and it's spring, sending the buffer and reciol spring out of the receiver extension.

It's pretty obvious from his description (as everyone else noted) that he didn't insert the receiver extension far enough into the lower to capture the buffer retainer.

[five.five-six]

An incorrect headspace will not remove the buffer retainer and it's spring, sending the buffer and reciol spring out of the receiver extension.

It's pretty obvious from his description (as everyone else noted) that he didn't insert the receiver extension far enough into the lower to capture the buffer retainer.

ok I believe you but what is a reciever extension? is it like a buffer tube?....maby i am missing a part in my lowers... thanks

[five.five-six]

Receiver Extension is the correct nomenclature for what is commonly referred to as a "buffer tube".

ok so the buffer detent would pop out... how does that keep the bolt from closing?? apperently this has happened to several people


just noticed that was my 100th post I am now a senior member :0)

[TonyM]

ok so the buffer detent would pop out... how does that keep the bolt from closing?? apperently this has happened to several people

Well, the retainer could pop up and out after the bolt carrier started to return into battery. This could make the retainer catch the rear lip of the bolt carrier. Grab your upper and look at the Bolt carrier if you can't visualize it.

[five.five-six]

Well, the retainer could pop up and out after the bolt carrier started to return into battery. This could make the retainer catch the rear lip of the bolt carrier. Grab your upper and look at the Bolt carrier if you can't visualize it.

i will liik at it his evening.. how many ft/lb should the reciever extension be tordqued? should I use anti-sieze? or lock tight? i do not want to have this problem