Bought this gun last night from someone locally who stated they shot a single 20rd box through it (sure looked that way) and took it out to the range today. I brought a total of 180 rounds with me and 4 mags. Mags were a gen 3 pmag, a daniel defense mag, a ETS mag, and a Lancer L5AWM.  Ammo was 100rds of brass cased federal champion 55gr .223, 40rds of American Eagle brass cased 55gr 5.56, 20rds of Monarch 55gr lacquer coated steel case .223, and 20rds of Tula 55r steel case .223.

I should note that I gave the gun a good cleaning and lube last night before taking it out today






The first 2 mags went through without hiccup. After those two mags I started experiencing FTE / FTF's. It happened in every single one of the 4 different mags, with all the ammo types, so that would eliminate it being a mag or ammo issue. I would say out of the 180 rounds, It had about 13 or so failures. When it failed, it would try to feed a round with a spent casing still in the chamber (partially extracted), causing the round it was attempting to feed to nose dive into either the bottom of the chamber or the back of the partially extracted round which led to causing major bullet setback on the round trying to feed.








Twice it did this






Any ideas? What I experienced reminded me of the problems I was having with my Vepr 12 when trying to shoot walmart value pack ammo until I re-profiled the bottom of the bolt carrier and the trigger hammer.  Could the friction between the standard Serbian trigger hammer and bottom of my carrier be causing these problems? When I pull the carrier back over the hammer there is definitely a lot of contact, but there is not much wear after 180rds today.


Internals / bottom of carrier and bolt look normal today with no odd wear or gouges anywhere (except for the marks where the round jammed into it nose first below chamber)










Lastly........The dust cover seemed to be deflecting the rounds, or at least some of them, during ejection like right where it is on an AR15.......this normal?

Did you shoot the steel/laquered stuff before the brass?

I did the 140 rounds of brass first.  

when I cleaned it, I did not do a full break down of the bolt. Its been suggested to me that it could be gunked up under the extractor causing it not to work as good as it should. When I shake the bolt, the firing pin does not move at all or rattle, so that tells me there is definitely gunk somewhere inside of it

Yes, there is probably junk from machining and etc they didnt clean off.

Clean it REALLY well and lube the shit out of it and go fore 500 more rounds. Should be fine.

another 660 rounds through it today, still had the same thing happen. Gun ran fine for the first 3 mags then as it heated up it would have the same random failures, not extracting the spent case sometimes causing the next live round to stovepipe. Since my last post, I fully broke the bolt down, cleaned everything, put in a brand new extractor spring, put in a +15% extra power recoil spring, polished some stuff up, gave the chamber a good scrubbing, etc.  Any ideas as to whats going on?

can you get pictures of the bolt face specifically the extractor?

Ill take one now, itll be up in 5 min

Hmm the extractor looks good. when the round fails to extract can you clear the set backed round, remove the mag, let the carrier go home, then pull back on the charging handle to clear the stuck case? or does it require a cleaning rod and pounding to clear? what I'm getting at is if the casing requires a rod and hammer you probably have a bur or a tight chamber. it could also be wayy overgassed can you post a picture of the inside front of the rear trunnion?

When the round fails to extract, all I need to do is drop the mag, let the live stovepiped round fall free through the magwell, let the carrier go home and run the charging handle again and the spent casing comes out with no problem. I could actually pull it out with my fingernail if needed. Just got to work so cant post pics of the front / rear trunnion until tonight but I dont see any unusual wear, really no wear at all.
Theory on akfiles is that it might be overgassed causing the extractor to slip, but if it was overgassed shouldnt it fail pretty much every shot vs work 75% of the time?  Also, it seemed to fail more without the booster brake then with, so I would think if it was overgassed it would run better without the booster if anything. This one has be confused for sure

did the issue get worse or better when you added the extra power recoil spring? here's the area you need to look at circled in red, if that area has paint missing/marks then it's over gassed.

Meant to ask you, on the second range trip did you happen to try any metal mags? Noticed that your first trip was all with polymer. Probably has nothing to do it with it, but at this point I think everything should be considered.

I see you mentioned on the second trip that it ran fine until it got hot, heat can and will make plastic expand some, possibly even the polymer magwell, and if it's a bit off to start with but still within spec when cold, then possibly the heat could push it dimensionally enough to malfunction?

Kinda grasping at straws here but you never know.  I've been working on cars and electronics my whole adult life, and I promise you the last thing you ever want to say is "that isn't possible", because that's precisely when Murphy's law takes a giant crap on ya, lol.

good thoughts.......I did try a metal mag that came with it.............come to think of it, I dont think i had a failure when using that mag but I only used it twice. I also dont recall having a failure with any of the steel cased stuff I shot, if I recall correctly they were all with brass. In stead of going by memory, this weekend when I go back out again Im going to bring a notepad and actually document every failure and if the ammo was brass or steel, and if the mag was polymer or metal. Im going to run the metal mag a lot more this weekend and see what happens

Rear Trunnion.........with a 600 lumen streamlight on it, it has more wear that I can see when I just pop the dust cover





Front Trunnion





Center Support has very minor rub mark in center



Lastly.........bolt has this half circle spot that almost looks like its grinded some, not sure if its supposed to be there or if this is wear from hitting on something repeatedly?

Here is the round in the bolt.....if i tilt the bolt upside down / sideways / etc the round stays just as straight




Here is how its grabbing the case rim






Chamber....I had hit it with a 45 cal bronze brush wrapped in a little 0000 steel wool with fitz polish in a drill at low speed, followed by a 45 cal MOP at low speed.......very minor tooling lines and it appears to be very smooth. If i slightly tilt the receiver back with a round in it, the round will slide right out. If I barely put a round in the chamber and slightly tilt it forward, it will slide right in.

For sure, and make sure and check both types of mags both cold and hot.  You'll get this figured out, I guarantee it.

Just dropped another $110 on ammo to go back out this weekend. Up until now, Ive been shooting the same Federal 100rd bulk pack brass with a little Tula / Monarch steel case thrown in.........This time, I got way more tula / monarch steel case, and a 100 rounds of different brand brass (monarch, winchester).......After thinking last night, I dont recall having any of the problems with steel case, so maybe this gun just does not like brass or at least the particular federal brass Ive been shooting? Depending on the outcome of this weekends range trip, it might be up for sale for a very good price for someone who may want to mess with it

Did you clean the gas port area?  could be some gunk in there reducing gas and reducing carrier momentum and not fully extracting empties.

yea gas port was cleaned and hot water was poured through the hole in the gas block to make sure its not obstructed and dripped out the barrel pretty good

Update after this weekends range session. For whatever reason, this gun hates brass. All steel cased ammo in all mags ran flawlessly, same mags with a few different brands of brass ammo had the same issues. Upon looking at the casings, all the steel (tula and monarch) had a more sharper grooved channel for the extractor to grab on to, where as all the brass (monarch, gold dot, federal, etc) it was more tapered. Extractor issue is the diagnosis at this point, but its an AK, so as long as it eats steel reliably im good.  I will take it out again this weekend and only shoot steel, if it runs 100% reliably again Ill call it a day and start building this as an SBR

Nope.....its freaking impossible to find a .223 / 5.56 AK extractor

Did you finalize that decision on steel cased?

My experience is that many people buy an AK just to shoot steel, as it is still pretty cheap, relative to most brass ammo.

I have a C93 HK clone because it loves steel cases. Some of those are known to not like brass very much. Century builds can be inconsistent to say the least. Mine likes both.

I have a M85NP because it shoots steel cased, and have had 0 problems with it using only steel. Never even thought to try brass in it. Now I will have to try that to see what happens>.....??

Thankfully Century does not "make" that gun....

Wound up having the same problems on the next range trip with just steel case too.............sold it and got the M92 which has ran flawlessly