• If you enjoy the forum please consider supporting it by signing up for a NES Membership  The benefits pay for the membership many times over.

AR47 pistol FTE

Rating - 0%
0   0   0
Joined
Apr 14, 2010
Messages
94
Likes
7
Location
NH
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 spring
f650cb085ed1097ca3a653f8ac3945db.jpg
4024e65855d15ae1dab2d7e8b78fe195.jpg
c17da83ace45c1a0badf0aa7ecd428dc.jpg


Sent from my XT1585 using Tapatalk
 

mac1911

NES Member
Rating - 100%
74   0   0
Joined
Dec 26, 2008
Messages
32,900
Likes
11,279
is the piston kit designed for 5.56 or 7.62x39? Also do you have a adjustable gas block?
is your barrel port lined up well with the gas block?
 
Rating - 0%
0   0   0
Joined
Apr 14, 2010
Messages
94
Likes
7
Location
NH
The block is adjustable and properly lined up but it was designed for 556. I have seen a few other threads and videos of guys running the same system on working AR47s

Sent from my XT1585 using Tapatalk
 
Rating - 0%
0   0   0
Joined
Apr 14, 2010
Messages
94
Likes
7
Location
NH
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
 
Rating - 0%
0   0   0
Joined
Apr 14, 2010
Messages
94
Likes
7
Location
NH
Have you considered changing out your extractor spring, going to an H3 buffer, or a more maybe using a heavier buffer spring?
This weekend I'm going to switch the gas system over to a DI system to rule out the piston variable. Depending on what happens then the heavier buffer is next on the list to try.

Sent from my XT1585 using Tapatalk
 
Rating - 0%
0   0   0
Joined
Apr 14, 2010
Messages
94
Likes
7
Location
NH
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
 
Rating - 0%
0   0   0
Joined
Apr 14, 2010
Messages
94
Likes
7
Location
NH
You measure the gas port while the block was off?
The size of the actual hole? No I didn't but the manufacturer says it's the same size as a 556 port which I think is my problem cause 7.62x39 doesn't have the same pressure as the 556. I think it would make sense the hole has to be opened up to make up the difference? Along with a heavy buffer to add more time for the case to cool so it's easier to extract.

Sent from my XT1585 using Tapatalk
 
Top Bottom