Ak 47 ejection problems

[red87yj]

Hi all,

I was hoping to tap into the plethora of knowledge on this board!

I'm having some troubles with a home built ak. The rifle will eject perfectly about 40% of the time, about 10 ft out at 1:30-2:00. About 30% of the time the case will just bobble out of the reciever and fall with in 2-3 feet at about 3:00. The remaining cases don't make it out of the rifle and cause the bolt carrier not to drive home.

I have tried 2 recievers with the same results (my error possibly) I pulled the bolt apart today and cleaned it very well. I then tried to run the rifle dry to see if there was any change. There was none. At this point I'm thinking gassing may be a problem because when I run the action by hand there is zero problems. I am using different mags but surplus ammo. Any input would be greatly appreciated


Thanks in advance!

[MovingtoAmerica]

Sounds like a gas problem to me. Is the gas block fitted/aligned correctly?

[aubie515]

I would start with the gas system. I'd also see if you can get your hands on a factory built AK and use your ammo/mags in the factory AK.

You need to narrow down what could be causing your issue to rule out items, but like I said I'd start with looking at the gas system.

[Hodgie]

Sounds like a gas problem to me. Is the gas block fitted/aligned correctly?

Possible under gassing issue. I had the same exact issue with a brand new DDI sent it and and found the receiver was out of spec they replaced it and the rifle runs like a top now.

[Nate7667]

Did you populate your own barrel?
Did you drill the gas hole if so?
The AK gas blocks are pretty generous on front to back and side to side with the amount of area available to achieve gas flow, compared to the AR.
It would have to pretty out of alignment, like cant get the gas tube on and locked in place with the rear sight base out of alignment.
But to be sure, take off the upper hand guard gas tube and shine a light down into the gas block to see if you can see the gas port.

How did you try 2 different receivers?
Did you actually press in the barrel, head space, pin it, test fire, press out, grab another receiver, press in, head space and test again?
Damn son!
Have you looked at the ejectors on the receiver?
Are both receivers from the same manufacture?

[USMC3531]

Did you populate your own barrel?
How did you try 2 different receivers? ?

probably a screw build.

100% receiver of flat/blank? whats the biggest drillbit that will fit through the gasblock and barrel?

try a box of "good" ammo and make sure there is no binding in the receiver also make sure the ejector isnt trimmed too short, and there isnt too much side to side play between the bolt and receiver.

[Gunsnwater]

Hows your piston?

[Noah_Zark]

Yes, the piston should NOT be screwed tight into the carrier; it should be 1/2 to 1 turn loose and cross pinned. The "wobble" in the piston allows for some misalignment and contributes to reliability.

Post a pic of the ejector divided to the inside left of the receiver.

Noah

[Nate7667]

probably a screw build.

I always forget about those, its just not "the way" lol

[Bang]

I'm wondering about the extractor. Sounds intermittent. 40% works, 30% prematurely slipping from the rim, the rest of the time just extracting before slipping off or enough delayed pressure pops the shell from the chamber. If the extractor is slipping off, look for timing issue. Case still clinging to chamber because pressure is still high, or over-gassing is over-driving the BG. Try measuring the rims/rebated areas to see if they are in spec. Does the BC go back far enough to start to pick up the next round?

Also, try measuring the rims/rebated areas to see if they are in spec. Make sure it isn't the ammo before beating up the rifle. Check for inconsistent propellant loads. Do you have access to a chronograph?