Problems with Krink: Bolt over base malf.

[1911-A1]

I just installed a new recoil spring in my Bulgarian 5.45mm AKS-74U. I had been having feed issues and tried that as a remedy.

It's firing two rounds, with a bolt over base malfunction on the third. If I fire rapidly, I can sometimes get more shots off between malfunctions, but it always happens, regardless of magazine, ammo type or muzzle device I use.

What other factors am I missing here?

[RetroRevolver77]

Did you check the barrel for a grommet in the gas port? Chances are it's a chopped down Bulgarian but some came in with grommets though usually in the 7.62x39 line. I'd contact Chris at AK-USA to see what he thinks.

http://www.ak-103.com/contact.html

[1911-A1]

Did you check the barrel for a grommet in the gas port? Chances are it's a chopped down Bulgarian but some came in with grommets though usually in the 7.62x39 line. I'd contact Chris at AK-USA to see what he thinks.

http://www.ak-103.com/contact.html

No, there's not one installed.

[RetroRevolver77]

No, there's not one installed.

Try an extra power recoil spring from Wolff. Brownells carries them, if that doesn't work, contact Chris. He's been building and working on AK's longer than anyone else currently still fixing them. Also check the selector stop to make sure it's 74 and not AKM- only because the AKM is slightly thicker and causes the magazine to seat at a slight angle. Easy way to tell is to look at the magazine to see if the back edge is sitting parallel to the bolt carrier rails, if it's ever so slightly off then it might be the wrong selector stop.

[Bret]

Can you provide more information about the build? What receiver? From a demilled or virgin kit? What barrel? Do you know who built it?

[RetroRevolver77]

Does your bullet feed guide have two guide cuts like this:

https://www.k-var.com/bullet-guide-f...senal-bulgaria

[1911-A1]

Can you provide more information about the build? What receiver? From a demilled or virgin kit? What barrel? Do you know who built it?

I bought it 12 years ago as a carbine with a pinned stock and fake suppressor. After the SBR papers, I had it restored. It's Bulgarian on an ITM Arms receiver. It was bought on GB, listed as an Ohio Ordnance build, but later when I contacted them about SBR conversion, they claimed never to have built it. I got it at a time when these guns were like hen's teeth, so I didn't have the luxury of buying a factory built rifle.

It was probably built during the AWB, hence the pinned stock. I got it in 2005 after the ban sunset.

[Peshawar]

Years ago I had a similar issue. It was a problem where the magazine wouldn’t seat far enough up into the gun for the bolt to reliably strip rounds from the mag.

Basically, above the mag catch on the bottom of the gun is a selector stop that is often milled to achieve the proper height and angle for feeding. At real AK factories they have gauges for this to determine how much to mill off the selector stop’s downward facing area where the magazine lug rests.

What could have happened is that your mag catch has worn sufficiently over years of use to be now preventing the mag from sitting high enough for reliable feeding. Thus, the bolt skimming and missing the rear of the round as it sits in the mag upon cycling.

Remedies could be using different mags which sit higher and allow a more parallel interface beteeen the rails, carrier / bolt line of travel, and magazine. Second, you could attempt to replace just the mag catch and hope that a tighter fit of the mag lug to the selector stop will fix the issue. Or three, have an AK smith refit the selector stop plate and then also replace the mag catch.

Good luck in however you decide to proceed.

-P.

[1911-A1]

Years ago I had a similar issue. It was a problem where the magazine wouldn’t seat far enough up into the gun for the bolt to reliably strip rounds from the mag.

Basically, above the mag catch on the bottom of the gun is a selector stop that is often milled to achieve the proper height and angle for feeding. At real AK factories they have gauges for this to determine how much to mill off the selector stop’s downward facing area where the magazine lug rests.

What could have happened is that your mag catch has worn sufficiently over years of use to be now preventing the mag from sitting high enough for reliable feeding. Thus, the bolt skimming and missing the rear of the round as it sits in the mag upon cycling.

Remedies could be using different mags which sit higher and allow a more parallel interface beteeen the rails, carrier / bolt line of travel, and magazine. Second, you could attempt to replace just the mag catch and hope that a tighter fit of the mag lug to the selector stop will fix the issue. Or three, have an AK smith refit the selector stop plate and then also replace the mag catch.

Good luck in however you decide to proceed.

-P.

I have about 25-ish 5.45 mags. All surplus. I wonder if trying magpul mags would be a good idea. Do they fit tighter? I'll check the fitment of the stop you mentioned. Thanks!

[Peshawar]

I have about 25-ish 5.45 mags. All surplus. I wonder if trying magpul mags would be a good idea. Do they fit tighter? I'll check the fitment of the stop you mentioned. Thanks!

Tightness isn't necessarily what you're looking for here. There are millions of AK's out there that exhibit a loose-ish fit when it comes to mags. In your case, if I'm correct, it's more an issue of the angle of the rear of the magazine as it sits in the gun. One way to determine what's going on is to use a loaded mag (hopefully you have a safe place to do this or you could use dummy rounds) in the rifle. Open the top cover so you can see what's going on inside, draw the carrier to the rear and then examine what you see as you allow it to to slowly move forward. Basically just slowly and carefully hand cycle it. Does the bolt face contact the rear of the top cartridge in the magazine with a fair amount of its area, or is the bolt just barely skimming the topmost cartridge where it's obvious that upon quick cycling it's missing rounds, or perhaps glancing and then bumping rounds downward back into the mag because it's contacting so little area on the rear of the cartridge?

If the problem is what I suspect, then you're not getting a lot of contact between the bolt face and the top cartridge of the mag.

To remedy, it could indeed be solved with different magazines. Check the ones you have, some may indeed be ok. To repair this issue properly isn't very simple. It will require someone with AK building / fixing knowhow that has the tools to drill out the trigger guard rivets, refit the selector stop, and then re-rivet it all back into place. I'm hoping you can just find some mags that will resolve it.

Try the hand cycling and let us know what you see.

Best,
-P.