Survivalist Forum banner
1 - 20 of 112 Posts

·
Pull up your Dora panties
Joined
·
7,377 Posts
Discussion Starter · #1 ·
i'm trying to help out a friend. i am not a fan of the rifles, nor am i a hater. i dont prefer ak's, i am just not a fan of any automatic rifle. regaurdless, i have customized several for friends and solved minor problems for them too, but this is more then i can figure so i need some help before telling him to take it to the smithy.

when he gave the rifle to me it would only fire one round and imediatly fail. it would not extract nor eject the case. it would fire the round in the chamber, and that was it. you would have to pull back the charging handle inorder to extract, eject and load the next round. this is where i started. i took the bokt out and inspected to insure the extractor did not appear broken. it seems ok, so i oiled lightly and reinstalled.

something happened when i oiled and reinstalled, because now it would extract and eject the case. not very far, 4-6 feet. most of the time i'm use to twice this distance or more. the next round would not chamber. it doesnt jam, it doesnt even attempt to feed. so my next thought was bad magazine. i switch mags, and no difference, switched mags again and still no difference. i used factory metal, i used composite promags(2), and no difference.

at this point i decide the gas tube MUST be partially clogged. but i have read so many threads about how thats not posibble and how you shouldnt clean the gas tube. but other s say yes clean it often, and yet others say only claen if you have an issue. so i sat down and i broke the AR down into pieces. little tiny pieces. as far as i could.
de-carbed, scrubbed, cleaned, lubed, the whole nine yard. made sure i hade flow through the gas tube and cleaned it as best i could. then i tore the bolt down and cleaned it spotless. removed the main spring and inspected. everything was spotless, and lightly oiled when done. pot everything back together and went out in the yard about 10:30pm. fired 3 rounds through it, and still they extract, and eject, but the next round will not chamber.

whats up with this???sometimes the bolt locks back after the last round, but not always. could it be the main return spring is too strong and this AR needs a lighterr spring?? i dont know much about this rifle yet i probably know more then the owner because he just bought it at a gun show and it was used. while the lower all appears to be a bushmaster, the upper i'm not positive about. the stock is definatly aftermarket, as is the front hand guard, and i believe the pistol grip has even been changed.

one thing i did not do was remove the gas tube. i was unable to find instructions on how to do that. i did read that i should remove it and verify that it lines up with the hole in the barrel, but i did not do this since i didnt want to force something that i was unsure of.

help, and or suggestions would be a blessing. thanks
vincent
 

·
Experiment 626
Joined
·
2,311 Posts
In addition to the gas tube, make sure you check the bolt carrier key... which is the open tube on top of the bolt carrier. You should be able to run a pipe cleaner into it and see it come out inside of the bolt carrier. Often times, someone will try to clean it with a Q-tip and lose the head of the Q-tip inside of the carrier key.

Check to see if the bend in the gas tube curves with the barrel near the receiver. Sometimes people remove them and re-install them upside down.

Have you tried different ammo?

If possible, maybe you can remove your handguards and take a pic and post it?

Edit: I have built a lot of ARs. With some good pics, I might be able to see a problem. I can also talk you through removing the gas tube.. it just requires a small punch to remove the tiny retainer pin in the front sight assembly if you have a standard front sight.

This gas tube is upside down. Notice how towards the receiver, it drops down towards the barrel, instead of rising with the barrel as it thickens at the chamber.
 

·
Garbage Collector
Joined
·
11,363 Posts
Check the magazine and ammo as well, crappy mags and funky ammo cause weird issues as well.
 

·
Pull up your Dora panties
Joined
·
7,377 Posts
Discussion Starter · #4 ·
Gas tube definalty bends the correct direction. I looked for that, i also looked to see if it was damaged and or bent anywhere it shouldnt be. I had no pipe cleaners, so i just used a can of cleaner with a little red tube for forcing the cleaner into it. I allowed this to soak for a few minutes, then i pumped almost a half a can through it at full pressure to flush it, then i proceeded to clean the barrel to remove any residue . The carrier key appeared to be clear, i clushed it out to and the cleaner flowed straight through without impeedment.

The first ammo used was pmc 55 gr, the ammo i'm using now is goergia armory reloads. Both of these work well in every other ar i've tried them in for test comparison.
 

·
space samurai
Joined
·
455 Posts
try squirting some brake cleaner down the gas tube. let it sit for a minute, blow it out with canned air, then flush it with some gun cleaner, and hit it with a pipe cleaner. if there is some junk in there, you may need to be more aggressive with the solvent, and need something to push the junk out (pipe cleaner).

sounds like your friend bought someone elses problem.

also, the spring might be binding on something that got in the tube. infact someone could have messed up the spring and that could be the problem in and of itself.

oh, and try it with a pmag.

imho your either not getting enough gas, your spring isnt compressing all the way back, or the mags are messed up. i dont like bushy mags.
 

·
Registered
Joined
·
1,036 Posts
Have you checked for a dry bolt. If the bolts dry put a light coat of grease on it then oil the hell out of it. Needs to be almost dripping with oil.
 

·
Pull up your Dora panties
Joined
·
7,377 Posts
Discussion Starter · #7 ·
try squirting some brake cleaner down the gas tube. let it sit for a minute, blow it out with canned air, then flush it with some gun cleaner, and hit it with a pipe cleaner. if there is some junk in there, you may need to be more aggressive with the solvent, and need something to push the junk out (pipe cleaner).
this is exactly what i did using a mixture of break clean, and hops#9. but no pipe cleaners.
sounds like your friend bought someone elses problem.
i totally agree and i said as much to him. thats how it ended up in my lap. thats what best friends do i guess. next time i keep my mouth shut:rolleyes:

.
i definatly need to find really long pipe cleaners, but i'm getting concerned about the rear spring
 

·
Pull up your Dora panties
Joined
·
7,377 Posts
Discussion Starter · #8 ·
Have you checked for a dry bolt. If the bolts dry put a light coat of grease on it then oil the hell out of it. Needs to be almost dripping with oil.
the entire gun was bone dry, i didnt want to over do it so i lubed bolt lightly and evenly with a couple drops directly to the points where it slides in the action.
 

·
Registered
Joined
·
258 Posts
What front sight or gas block is on the gun?

I had a rifle that was having a similar issue and it turned out that the hole in the gasblock didn't line up with the hole in the barrel...

- Clint
 

·
Pull up your Dora panties
Joined
·
7,377 Posts
Discussion Starter · #10 ·
What front sight or gas block is on the gun?

I had a rifle that was having a similar issue and it turned out that the hole in the gasblock didn't line up with the hole in the barrel...

- Clint
thats what one person at my local shop said, but i need to remove the gas tube inorder to inspect. probably going to happen tonight.
 

·
Opinionated old fart.
Joined
·
8,046 Posts
The chamber is filthy. That's why the shells would jam up after each shot. When you cleaned and lubricated the BCG, it helped a little in the operation, but not enough.

RTFI. Before doing any more work on this weapon download and read the military instructions and clean using a 5.56 chamber brush.

Also - Promags are junk. Get some Pmags.
 

·
that's like, your opinion
Joined
·
17,825 Posts
Vincent my man... it sounds to me like you are loosing pressure after the gas key. I think the culprit might be the gas rings around the base of the bolt face... sometimes these 3 little rings can align perfectly (so that you have the cut openings of these rings all in a straight line). this will cause the gas being redirected through the gas key to escape, hence the loss of pressure....

so i would recommend a couple of things,
1. inspect the gas rings and ensure the openings are rotated away from one another
2. the rings themselves might not be dimentioned correctly or have been damaged, in which case i would suggest replacement

midway has a huge selection of these from 2 bucks up to 20... DPMS actually makes a one piece ring so that this problem can be eliminated, it will cost you 4 bucks plus s&h

http://www.midwayusa.com/Search/#gas rings____-_1-2-4_8-16-32
 

·
that's like, your opinion
Joined
·
17,825 Posts
Vincent my man... it sounds to me like you are loosing pressure after the gas key. I think the culprit might be the gas rings around the base of the bolt face... sometimes these 3 little rings can align perfectly (so that you have the cut openings of these rings all in a straight line). this will cause the gas being redirected through the gas key to escape, hence the loss of pressure....

so i would recommend a couple of things,
1. inspect the gas rings and ensure the openings are rotated away from one another
2. the rings themselves might not be dimentioned correctly or have been damaged, in which case i would suggest replacement

midway has a huge selection of these from 2 bucks up to 20... DPMS actually makes a one piece ring so that this problem can be eliminated, it will cost you 4 bucks plus s&h

http://www.midwayusa.com/Search/#gas rings____-_1-2-4_8-16-32
in case you dont know where these babies are they are item #52 on the attached schematic...
 

Attachments

·
Pull up your Dora panties
Joined
·
7,377 Posts
Discussion Starter · #15 ·
Vincent my man... it sounds to me like you are loosing pressure after the gas key. I think the culprit might be the gas rings around the base of the bolt face... sometimes these 3 little rings can align perfectly (so that you have the cut openings of these rings all in a straight line). this will cause the gas being redirected through the gas key to escape, hence the loss of pressure....

so i would recommend a couple of things,
1. inspect the gas rings and ensure the openings are rotated away from one another
2. the rings themselves might not be dimentioned correctly or have been damaged, in which case i would suggest replacement

midway has a huge selection of these from 2 bucks up to 20... DPMS actually makes a one piece ring so that this problem can be eliminated, it will cost you 4 bucks plus s&h

http://www.midwayusa.com/Search/#gas rings____-_1-2-4_8-16-32
so your saying the rings need to be staggered just like the piston rings on a V8 or oil will blow by. cool, i will look for that too.
 
  • Like
Reactions: mefunkymxw

·
Pull up your Dora panties
Joined
·
7,377 Posts
Discussion Starter · #16 ·
are all gas tubes the same length and gauge? do i need to order a specific one if i'm goin got replace it, or are they universal??? at this point i am reafirming the decission to never own one of these. fun to shoot in the back yard periodicly, but i've never had this much of a pain with my lever guns. i feel for you guys and your shiney black guns
 

·
that's like, your opinion
Joined
·
17,825 Posts
incidentally, how many rounds has your buddy shot through this thing????? is it brand new... if so, the flash hole in the barrel might not have been aligned properly with the gas block.
 

·
that's like, your opinion
Joined
·
17,825 Posts
are all gas tubes the same length and gauge? do i need to order a specific one if i'm goin got replace it, or are they universal??? at this point i am reafirming the decission to never own one of these. fun to shoot in the back yard periodicly, but i've never had this much of a pain with my lever guns. i feel for you guys and your shiney black guns
you should only feel for AR15 owners... i tend to shy away from DGI ARs

you should have titled this thread "yet another reason not to own an AR" lol :rofl:
 
1 - 20 of 112 Posts
Top