AR47 pistol FTE

Hi before everyone jumps on how the AR47 shouldn't exist and I told you they never work, I knew what I was getting into and did it strictly as a fun different range project. After building multiple ARs I wanted the challenge of getting something like this to run reliably. I'm having FTE/Short stroke issues with brass or cheap steel ammo case ammo. Ive tried loading different ASC mags with different round counts and It never locks open on the last round and always fail to eject half way like in the pics. Now I tried just loading in one round without a mag in and it does eject and the case going to the 4-5 o clock area. Now the last pic is with no mag in and it seems like an ejector issue cause the bolt goes all the way back but the round failed to flip out.

Barrel-- is a 10.5 inch YHM 7.62X39 barrel with a YHM phantom flash hider

GAS SYSTEM-- Adam arms piston kit.

Bolt-- MGI with extended firing pin

BC-- Adam arms new anti tilt bolt carrier

Stock-- Shockwave blade with pistol springhttps://uploads.tapatalk-cdn.com/201...52fc4df61b.jpghttps://uploads.tapatalk-cdn.com/201...2f7ba6a607.jpghttps://uploads.tapatalk-cdn.com/201...736c34a074.jpg

Sent from my XT1585 using Tapatalk

Had the same issue FTE issue with mine. Same barrel length but DI.
I did the same mag checks then I found that I had a broken extractor.
I replaced it and haven't had a hiccup since.
You may have to increase the gas for your lock back issue.

Had a similar issue with an AA upper in 5.45, turned out to be the BCG according to them. Sent them the whole upper was too heavy, they have a lighter version of their piston BCG.

Attachment 47918

Quote:

---

Originally Posted by Smokin338

Had a similar issue with an AA upper in 5.45, turned out to be the BCG according to them. Sent them the whole upper was too heavy, they have a lighter version of their piston BCG.

Attachment 47918

---

Thank you that's an awesome chart and ya it's definitely hitting 430-600 area cause I'm a lefty and it hits my right shoulder ejecting which I've never had happen before. I'll look into there lighter carrier if it doesn't fix this it will still be good to have around for my other ARs.

Sent from my XT1585 using Tapatalk

So I finally got the AA lightweight bolt carrier and the FTE is actually worse now. The cases only come out of the chamber about 1/3 of the case length. So I'm thinking it's definitely a under gas issue, between the 7.62x39s lower velocity and the 10.5 barrel I just don't think there's enough force to pull out the cases. I know they used a booster on the shorter barrel aks so I guess I'll try that before I open up the gas port.

Sent from my XT1585 using Tapatalk

I would look at that pistol spring as well. Mine ran like crap on an AR pistol.

So took a little longer then I planned but swapped out the bolt and gas system from the piston to DI and it made things worse. Now it barely pulls the case out maybe 1/4 of an in and the case is really hard to finish pulling out using the charging handle.

So I'm thinking there's not enough dwell time for the steel case to shrink back down and it's just too much force to extract it. So I'm thinking toss the piston system back in with the regular weight bcg and switch to a heavy buffer to give it a little more delay before it unlock and trys to extract.

Sent from my XT1585 using Tapatalk

Came back to update this thread for anyone who searches because they are having the same issues. I got it working flawlessly by drilling out the gas port to 1/8 of an inch. That solved all my issues so it's clearly under gassed using the same gas port size as the 556, which makes total sense seeing how much lower the pressure is on the x39 round compared to a 223/556 round.

Sent from my XT1585 using Tapatalk