Weird PSL hangup plus potential fix.

[20nickels]

Ever since I bought my PSL it hangs up about once every mag. The carrier sticks nearly all the way back. Will start to chamber a rd but stop part way. I simply smack the charging handle and the carrier flies forward and chambers every time. I've determined it's not the mags as It will do it hand cycling. I re-profiled and polished the hammer and the carrier bottom, much less resistance but still hangs up. There is seemingly nothing holding it back.... except the recoil spring bunching up inside the carrier tube/hole whatever. Ordered anther spring from Apex. Same thing.
Shootin' buddy bought an AK some time ago that came with one of those useless recoil buffers. I popped it in and now it doesn't hang up hand cycling but I'm worried it might short stroke the carrier and misfeed in actual firing. We will see when I shoot it next. I'll let you know.
Weird.

[Burnout]

What kind of PSL is it? (kit built, import)?

Sounds like maybe the hammer could be a tad high causing the B/C to bind up. I've had kit built AK's that did this as the G2 hammers can sit to high in some receivers if you are using one. If this is the case you could grind a new radius on the hammer.

Could be too that the rails are not aligned correctly with the trunion causing the bolt to get caught sometimes. Could be a number of things.........

Take the cover off and slowly hand cycle it and watch to see where you can feel it binding.

The buffer you are using is not really fixing it, just masking the problem.

[20nickels]

Originally Posted by Burnout

What kind of PSL is it? (kit built, import)?

Sounds like maybe the hammer could be a tad high causing the B/C to bind up. I've had kit built AK's that did this as the G2 hammers can sit to high in some receivers if you are using one. If this is the case you could grind a new radius on the hammer.

Could be too that the rails are not aligned correctly with the trunion causing the bolt to get caught sometimes. Could be a number of things.........

Take the cover off and slowly hand cycle it and watch to see where you can feel it binding.

The buffer you are using is not really fixing it, just masking the problem.

TGI Nodak squareback. I did all of that stuff, lol and I agree completely that the buffer is just a band aid.
The rails seemed straight but I'll check again. With the re profiled/polished hammer and the recoil spring assembly out the carrier runs very smooth w/ zero drag. Once I put the spring back in and pull it all the way back it's not hard to get it to stay back (no magazine). This led me to the recoil spring. Maybe it's not a stretch to say that this is just a byproduct of the lengthened RPK reciever. Do they use the same carrier as the RPK? Just add a longer piston and a longer spring to get wadded up in the carrier? Maybe I should polish the spring channel in the carrier? I'll look into that tonight.

[20nickels]

Slick, I'm using the 1/2" white one. Didn't know there were dif thicknesses, tks. I'll look into the Blackjack if I settle on a buffer.

[20nickels]

Rails are straight. Spring chanel in carrier is snag free.
Still Weird.

[Mark75H]

My NODAK Spud (built as square back) PSL does the same thing but less often. Mine will only stay back if you pull it back and ease it forward. I have chalked it up to the Tapco hammer not being worn in ... but then again, my spring may be weak as well ... even with a 1/16" restrictor in the gasblock I am still pitching empties about 30 feet.

Nickels, do you have a Tapco FCG in yours? Have you tried it with the hammer out? With my hammer out, my carrier slides like socks on the polished gym floor.

[Jaimenv]

With the dust cover removed, check and see if the recoil spring assembly forward rod that telescopes in to the rear tube that catches on the rear trunnion sticks out and catches.

The forward rod has a "T" shape of sorts.

You may want to disassemble the recoil spring assembly and check it for burs or anything that might be causing this.

[20nickels]

Originally Posted by Mark75H

Nickels, do you have a Tapco FCG in yours? Have you tried it with the hammer out? With my hammer out, my carrier slides like socks on the polished gym floor.

Yes, Reprofiled and polished Tapco and it's very smooth now. I did try it to check the rails but I'll try it again with the spring in. Good call. I did find a little leftover cosmo in the end of the spring channel but I doubt this is the prob and if it is that's borderline reliability for an AK variant.

Jaimenv, Had not thought of that. I'll check that too but I've tried two separate recoil assemblies already. Even traded springs to the one that fit the top cover rear better.

[arcom]

The buffer is the solution, and no, it won't cause a short stroke.

[20nickels]

Originally Posted by arcom

The buffer is the solution, and no, it won't cause a short stroke.

Do you have a preference on buffers?

[AKBLUE]

If the buffer cures the problem then I would conclude the carrier is catching on the rail inlets at the rear of the receiver. Just sort of rail jumping. If it sticks and you can remove tthe top cover and observe what is causing the hanging carrier. I doubt it is the hammer as that is at least an inch forward of the rer iof the receiver in terms of cycling distance.

Here is a detailed review of rail jumping and also relates to the carrier hanging at the rear vs fully jumping. This may be the cause & cure.

http://www.arizonaresponsesystems.co....shtml#anchor1

[Mark75H]

Originally Posted by AKBLUE

I doubt it is the hammer as that is at least an inch forward of the rer iof the receiver in terms of cycling distance.

About an inch from full back ... yep, that's where mine will stop if you baby it. Pull it back and let it fly like you are supposed to - no problem.

[arcom]

Do you have a preference on buffers?

To be honest, no. And definitely not to start a pro vs. con buffer argument, I put a buffer in every AK rifle I own IF it will function with it. Just my preference.

[andresere]

Spitballing here, take your upper handguard/gastube off, put the bolt carrier and spring back in and see if it does it then. Maybe the magazine pushes the carrier up enough to bind the piston in the gas tube. Does the piston have the freeplay from the carrier like it should?

[20nickels]

Originally Posted by andresere

Spitballing here, take your upper handguard/gastube off, put the bolt carrier and spring back in and see if it does it then. Maybe the magazine pushes the carrier up enough to bind the piston in the gas tube. Does the piston have the freeplay from the carrier like it should?

Tried that but tks for the response. I havn't had time to try it but AKBLUE may have the answer.

[20nickels]

Messed with it last night. I don't think it's jumping the rails. I'm convinced it's the spring because spring "A" bunches up much worse than spring "B", A has a slight kink in it that exacerbates under load. Nonetheless the buffer did cure the problem. I'll test fire on next range trip both shouldered and limp wristing it. If it is not 100% cycling I'll look into A thinner buffer and/or a stronger spring.
Mark said earlier that his does this as well. Maybe this is inherent to the Nodak Squareback, though I cannot see how. Doesn't Harlan (Nodak) post here? Anyway, there you have it.

[AKBLUE]

I have/built a PSL shorty on a squareback NDS receiver. No issues with cycling at all. I used a TAPCO G2 trigger group without mod.
Dunno., what your rifles issue is.
The spring assembly is pretty simple and unless damaged in some way it should be easy to decipher any problems.
Where is it hanging up exactly?

[20nickels]

Hand cycling the carrier it will stick all the way back, whatever this is applies drag to the carrier. Upon actual firing it gets past this but fails to chamber a round, usually gets a bullet pointing up and still half in the mag. Smack the handle and it flies forward chambering like it should.

[irierider]

I had the same problem on my square back bastard build 762x39 psl on a 1.6 square receiver... It came with a buffer that caused stove pipe/ftf problems every once in a while.. Took out the buffer same thing happen.. I noticed if i racked the handle and pulled up the pressure from the hammer caused it to almost field strip it self for lack of a better term (but the spring kept it from doing that so it just needed a smack) this pissed me off being it was a used gun i got on here... Kept at it finally i modded the buffer i had to be half the size where it mattered to keep it from hopping the rail, but thin enough to not shortstroke it and cause feeding issues.. Now i can rapid fire a 30rd mag no.problems.. Square backs are bastards in the psl world i guess..

[20nickels]

Finally got to shoot it. Problem still persists with the buffer installed but no short stroking in 30 rds of fire just hangups part way through the mag. Ejects and cycles the carrier completely when single loading them and shooting. I'm going to focus on the mags and mag well now. Most of the mags fit really tight fwiw. They need a smack on the bottom to stay locked in.

[arcom]

A lot of the early CETMEs made from basically new demilled rifles had the same problem. The solution was to lube the living snot out of the carrier and receiver innards for the first 100-200 rounds. I used WD in mine and it would splash out after every round. After around 125 rounds, it began to run more smoothly and after 150 rounds I rag wiped everything and never looked back. In the CETME's case the culprit was the cast receiver and grit left over from the assembly process.

How about swapping the TAPCO hammer and trigger for PSL parts? I do think the problem is with the TAPCO hammer being too tall and/or the trigger hooks not depressing the hammer enough when it cocks to allow the bolt carrier to move over it. If you remove the recoil guide and spring then move the carrier forward from the rear, there should be a some/slight amount of resistance as the carrier hits the hammer, forces it down about 1/8", then continues on to strip off a round and go into battery. If you have to force the carrier over the hammer, that might be the hang up. The problem is what constitutes too much force to get the carrier over the hammer? There is resistance but it should be smoothly overcome with forward pressure on the carrier.

If it were my PSL, I'd be bald by now from pulling out my hair. Good luck!

[Salvo]

You might check out my thread... Don't know if it will help or not, I still havent been able to get out to test fire it... But you may find my "fix" interesting...

http://www.akfiles.com/forums/showthread.php?t=110664

[Bolt2bounce]

If the buffer cures the problem then I would conclude the carrier is catching on the rail inlets at the rear of the receiver. Just sort of rail jumping. If it sticks and you can remove tthe top cover and observe what is causing the hanging carrier. I doubt it is the hammer as that is at least an inch forward of the rer iof the receiver in terms of cycling distance.

Here is a detailed review of rail jumping and also relates to the carrier hanging at the rear vs fully jumping. This may be the cause & cure.

Ak blue is correct... the hammer( ie/spring) is pushing the carrier up just enough to catch on the right upper corner of the..top of the receiver, not the rails that the carrier rider on down in the receiver channel, but the upper step down.....here is a test.. take the top cover off, take any recoil buffer out, but keep the spring and guide installed.. now pull the charging handle back and ease it forward..till it catches.. using the index finger press down very gently on the tip of the charging handle..far right side..the carrier will run / slam forward.. also you can see it will be lifting slightly on the right side slot in the carrier.. the cure.. is to either shim the recoil spring lug on the left side in the rear slot where it slides back into the rear trunnion.. you can also stone the edge where it is catching on the receiver and or add metal to the top rail or machine/ sand/polish the carrier where it is catching... the buffer will help the problem as it adds energy (bounce)and limits the carrier travel so it doesn't get caught at that point as easily.. this problems happens a lot on the Nodak receivers because they were machined to that spec.. the original receivers also suffer from it but less as they are usually hand fitted.. I've also run into it on the M76 receivers.. B2B

[arcom]

Here's a pic of an original Romanian hammer and a TAPCO G2 hammer. The G2 hammer was originally installed in an AMD65 home build (NoDak receiver) and was moderately re-contoured and highly polished on the nose where it meets the bolt carrier. Even with the addition of a +10% AK recoil spring, I could not get it to run 100%. My solution was to reinstall the original (Hungarian hammer) and use a US mag follower to meet 922r. It ran fine after the hammer swap.

TAPCO hammers are notorious for inducing sticky bolts in AKs and the usual solution for me was to polish the hammer and add a +10% spring. Unfortunately, as noted, it did not work in the case of the AMD65. In another build, a Romanian G AK, I used a Ewbanks receiver and while it was a nightmare to get it built, I did not have the sticky bolt problem from the git go.

The G2 pictured is an early build, around 2003, and I read somewhere that TAPCO changed the hammer contour in later builds. If you look closely at the pin holes you might see that the TAPCO is slightly higher.

HTH

[20nickels]

Tks guys, I'll put your advice to test tonight. It does have less than 160 rds through it, if I don't figure it out I may have to just run it wet until it (hopefully) breaks in.

[20nickels]

Finally got the rug rats to bed and had time to play with the PSL.

I've concluded I have/had 2 points of resistance. The buffer cured the recoil spring bunching up inside the carrier channel and the next point comes into play only with magazines in place. Try as I may I couldn't find any fault with the rails, but I'm not ruling anything out.

The bottom of the bolt is catching the top front tip of 6-7 out of my 8 total mags. Oddly enough though, that's not where it hangs up but it is definitely chattering over the top of them and that can't be good for reliable cycling. It still hangs up mostly while picking up a new round. I mentioned before they are a very tight fit in the mag catch. Are my magazines too high in the well? Anything I can do about that?

[Dan FS71]

We all know the general condition of most psl mags. Next time it happens put a sticker on that mag & repeat. More likely than not you will find it's the mag.


As the mag thins and loses intergrity it become much more suseptable to side loading. To confirm a suspect mag is the issue with this specific problem compair with a known good mag.

Load both mags. Push the full mag down as to load another round and see if you can get it to stick 'down'. Squeeze lightly on the front and back (not the sides) of the mag and the round should pop up.

Some light messageing usually can cure the issue if this is the culprite.

[20nickels]

Tks Dan, I will inspect each magazine for this.

Originally Posted by arcom

If it were my PSL, I'd be bald by now from pulling out my hair. Good luck!

I've remained surprisingly calm but I'm getting there, lol.

If nearly all of my mags are interfering with the bolt, something is wrong. It would appear that my magazines and bolt are too close together causing friction and drag. Babying it, it will even hang up on the rear of the follower of an empty magazine.

The easy fix would be to take a small amount material off the bottom of the bolt like I did for my Saiga 12 but this is a rifle running @ much higher pressures so I don't know if that is potentially dangerous or not. The other problem being that that is the part of the bolt that picks up a new rd. Between that and a bit of fitting of the mags, mag catch, or both.. the bolt should clear but I may be causing other problems.

[Jaimenv]

Once more remove the dustcover,recoil spring and carrier and bolt. Install a empty magazine, separate the bolt from the carrier and slide it forward while paying attention to the bolt underside catching on anything.

The fact that the magazine fit is tight could be a hint on the problem. Look and see if the magazine skewed to one side more than the other.

Also you could try this, with a empty magazine installed and the rifle assembled, get the bolt to hang up, then try and move the magazine from one side to the other see if the bolt rides forward when doing this, see which side makes it release.

[marktc223]

Just finished a build on a Nodak Spud receiver. The OEM machined areas on the rails are opened up too long and far forward for assembling the bolt carrier into the receiver. If you do not use a (Blackjack) buffer, the bolt carrier does travel far enough back to come to the stripdown/removal area on the rails. These openings for assembling the bolt/bolt carrier into the receiver should be as far back as possible and just long enough for that assembly to fall in. This is definately a screwup on the machining process on the Nodak Spud receiver and will cause a lockup of the carrier assembly without the use of a buffer to prevent that assembly from moving back to that poorly located machined rail area.

The pistol:

[AKBLUE]

I have not heard the problem you describe as an issue with the NDS receiver for the PSL. It appears you have installed a non-standard pistol type rear block. I would assume that is the issue and the configuration of that block is the problem or the setback of the block is too far to the rear allowing the carrier jump.
I built a PSL from a kit with NDS receiver and no rail jump issue at all.
It could also be that your recoil spring guide is set too far back in the rear block and is not trapping/stoppig the carrier from jumping the rails.

I bet that is a handful to shoot. Or maybe two handfuls.
I just had my PSL shorty out on Wednesday and with a 16" barrel and full buttstock it is a handful to shoot.

[20nickels]

Mean looking build Mark.

Along as this is BTT, I spoke with a local builder w/ a PSL and we think it's the magazine position in the well. They sit high causing serious drag. It seems I've come full circle and was foolish to discount the mags @ 1st. I fitted them this weekend and will take it to the range soon & report back. Tks to all for helping.

[gunplumber]

examine your bolt. There is a longitudinal radius cut that allows the bolt shaft to clear the ejector. The ends of it ramps up to the bolt shaft. Sometimes, there is a little step here. It can catch on the back of the ejector. Take a dremel cutoff wheel and kiss this step so that the ramp continues all the way to the shaft proper.

I suspect you are dealing with ejector clearance. There is a little wiggle in the bolt. Whin it is to the right, it clears fine. When it is to the left, it snags. check for wear marks.

hand cycling (pulling back and up) snagging is the ramp cut on the bolt carrier. Buffer works around. Cure is two fold. see http://www.arizonaresponsesystems.co...bleshoot.shtml