7.62x39 AR HELP!!

[Proline395]

Ok I have a spikes lower with a Delton upper in 7.62x39. After about 80 to 100 rounds the gun hangs an empty shell case at full battery. I have to use a block of wood to get the charging handle and BCG back then separate the upper from the lower and use a cleaning rod down the end of the barrel like a muzzle loader to tap out the empty casing. I cleaned and oiled the gun well and tried again....same story. HELP!!!

 

[tuj]

what ammo and gas system are you using?

 

[rcmodel]

I cleaned and oiled the gun well and tried again....same story. HELP!!!

But did you really clean the chamber enough to get all the burnt lacquer fouling and carbon out of it???

You need to use a dedicated chamber brush that fits the chamber, and spin it chucked in a cordless drill to get all the carbon out of the chamber.

http://www.midwayusa.com/product/51...ore-brush-762x39-russian-8-x-32-thread-bronze

rc

 

[mljdeckard]

From what I have heard about AK ammo uppers, they are very prone to problems. If it was me I would try every ammo and magazine combo I could.

Honestly, it's probably better to find an AK-style gun shooting 5.56 than an AR-style gun shooting 7.62x39.

 

[30 dirty 30's]

Check your spent casings for rings or bulges. Sometimes chambers have these imperfections and cause hang-ups. Also check your casings to see if the look stretched/galled, if the chamber has a rough surface all around it can cause problems after a little bit of shooting.

 

[Lloyd Smale]

Mine runs great on reloads or good quality factory ammo. Steal case russian crap will run in it but is so dirty that after less then a 100 rounds the 100 percent relibility wanes fast. My first advice would be to get a good chamber brush and clean your chamber real well and try it with some good ammo before you pass judgement. My gun is a bushmaster. Only thing i had to do to insure relibilty is change my mag springs out for wolf extra power ak47 springs and use good ammo. That dirty wolf crap works fine in a loose tolarance gun like an ak but ars are a bit more finiky when it comes to dirty ammo.

 

[rbernie]

I have several M1S 7.62x39 barrels that have relatively tight chambers. That's great for accuracy and slow fire, but if I let the barrel get too hot then the steel cased ammo starts sticking in the chamber.

So I don't use those barrels for metaphorically smoking the handguards.

 

[Proline395]

I was using the standard Wolf steel cased ammo because it is cheap....isn't that why we all shoot it? hahaha I have acquired the cleaning brush (thanks for the link) and will clean super well and retest with some brass cased factory loads I have also acquired. I checked the hung casing and from what I could tell it didn't look stretched or marked or anything like that. Thanks for the help!!

 

[rbernie]

You may find that the barrel's chamber is simply incompatible with steel cased ammo. If that proves the case, then you can either have the chamber reamed a wee bit larger or move to brass cased ammo.

 

[adelbridge]

My guess would be a tight chamber but it could be an extractor issue. Check to see how your empties are ejecting. If it does it again, slam the butt down on the ground while pulling the charging handle, you should be able to pogo the round out. If the round comes out that would indicate a tight chamber. If the cartridge slips off the extractor that would indicate a bad extractor or out of spec soft metal case. I am a huge fan of the 7.62x39 AR and to me running brass is not an option. I built mine purely for the economy and availability of cheap steel cased ammo.

Here is what I would do to fix it

Clean and polish chamber with chamber brush, drill and lapping compound

Install dual spring lobster tail extractor.

Call Del-Ton if above doesnt work

 

[dprice3844444]

put the extractor upgrade kit in it first,then try again

 

[wally]

but it could be an extractor issue.

Don't think so, the OP says the bolt is locked fully into battery after the shot and needs to be pogoed or pounded open which I assume then rips off the rim since he has to pound out the empty from the muzzle.

Did he get the chrome chamber option or cheap out? IMHO you really want a chrome chamber if you plan to shoot the cheap steel cased ammo in 5.45, 5.56, or 7.62 ARs.

I pretty much shoot nothing but cheap steel cased ammo (lots of it!) and the only times I've had the OP's issue it was FOD (a grain of sand) on the case that wedged the fired empty in the chamber.

Call Del-Ton if above doesn't work

I'd call Del-Ton before using power tools. Could easily be a rough or out of spec chamber, in which case they should fix it.

 

[Proline395]

I got the rifle from a friend who was HARD up for money so i paid him $500 for it with 300 rounds of ammo and 4 mags....I don't know if it has a chrome chamber or not. Where do I get this extractor upgrade kit?

 

[tuj]

Check out LMT's bolt for 7.62x39. They seem to have a very good reputation on the ar15 forum. Lots of people breaking extractors shooting steel wolf 7.62x39 over there...

But even upgrading the extractor, you should really have the chamber checked for specs. If out of spec, something could go bad....

 

[Proline395]

Thanks for all the help!!!

 

[Lloyd Smale]

Dont know if im just lucky or the bushmaster bolt is a better setup. Ive shot 3 full cases of wolf black box through mine along with probably as many reloads using brass cases and mine hasnt had a single issue.

 

[dprice3844444]

if the chamber is not chrome lined,might try lozok custom arms and have the chamber opened up a bit and melonite the barrel. upgrade kit brownells

 

[1stmarine]

Several things you can do:
- Get a stronger extractor and spring as others suggested.
- Make sure the system is not overgassed trying to extract too soon. An adjustable gas block can cure the problem.
- Avoid lackered or other 'sticky' rounds although I didnt have a problem trying with those. Mine is an AR Performance melonite barrel.
- Inspect the chamber and make sure it is ok and w/o rough spots from machining. Might want to check for any roughness and run some lapping compound although I don't recomend to be too shiny. There is enough bolt thrust as it is for an AR.

Good luck.

 

[tahunua001]

one thing that was taught to me in the navy for clearing stoppages of that nature is to slam the butt stock on the ground while applying pressure on the charging handle...

to your problem, I would say your chamber is out of spec or you are using crappy ammo. either way, try an extra thorough cleaning of your chamber and then inspecting for an burs or other imperfections, if present try a file to make it flush with the rest of the chamber or at least get rid of sharp edges...


however given the relatively high number of rounds between fails it just sounds like crappy ammo to me.

 

[navystang]

i recently finished an ar in 7.62 for my dad to hunt with and we had the same problem with the sticky chamber. i cleaned and cleaned the barrel and chamber or so i thought i even swapped lowers, buffers but i finally got it to extract the spent case after i took a shotgun bronze brush to the chamber and really cleaned the chamber. b/w we started shooting Herters but after cleaning the chamber we shot some wwb 7.62 we had laying around, cycled and extracted fine, try some good quality brass rounds then go from there good luck