AK 47 Bolt Hanging Issue

[esh21167]

I've been on AKFiles with this issue on my Polish underfolder for a bit and have received some pointers about how to proceed but wonder if anyone knows of someone in SE PA (I'm near Reading) that would be willing to give some FTF aid to a fellow PAFOA member. The BC hangs back and basically jumps off the rail. I'm considering polishing the 'ramp' area of the BC groove to remove burrs (red box) and slightly bending the rail upward, hoping that will help get the carrier to slide back onto the rail. Here's some pics and thanks.
BC-2.jpg

BC-1.jpg

20131020_100205_resized.jpg

20131020_095504_resized.jpg

[MT1]

I don't know of anyone in your area. The closest gunsmith I have dealt with is Carlisle Gun Works. The owner is Mike Kubarek. His prices and turn around time are good.

His shop is in his home and he is retired so he doesn't always answer the phone if he is working with a customer or on a gun. You have to leave a message. He returns calls within reliably.

If you are in the Carlisle area I would recommend making an appointment to have him look at your AK. His speciality is 1911s but he can fix just about anything.

www.carlislegunworks.com
717-254-6701

828 Hamilton St
Carlisle, PA 17013

[Bang]

I am not a gunsmith, but I have a couple of questions and thoughts.

I assume this occurs during actual fire. Can you duplicate it by manually actuating the BC?

Have you tried it (manually) with a test spring (just a wire-wound with less compression) so you can study the mechanics of the problem without fighting the stock spring?

Do you have access to someone else's (same) BC to see if remains or is eliminated?

Any peened/galled area is suspect. The assessment is, is the offending part already worn, and would cleaning it up take it farther out of tolerance?

How about the recoil spring itself? Could it be getting weak?

Bending the rail(s).... to correct them, maybe. To compensate...I'd go slowly.

[esh21167]

I am not a gunsmith, but I have a couple of questions and thoughts.

I assume this occurs during actual fire. Can you duplicate it by manually actuating the BC?

Have you tried it (manually) with a test spring (just a wire-wound with less compression) so you can study the mechanics of the problem without fighting the stock spring?

Do you have access to someone else's (same) BC to see if remains or is eliminated?

Any peened/galled area is suspect. The assessment is, is the offending part already worn, and would cleaning it up take it farther out of tolerance?

How about the recoil spring itself? Could it be getting weak?

Bending the rail(s).... to correct them, maybe. To compensate...I'd go slowly.

I purchased this as an 'assembled kit' with the seller disclosing a bolt hanging issue, but some had said that's a common G2 hammer issue, so I wasn't quite expecting this type of issue. So I haven't fired it yet. I wanted to get this corrected first.

It hangs even when I rapidly pull and release the bolt. I have to really whack the bolt down to get it to go forward. Tried another BC and same thing. Also have worked it without the spring and the bolt and the BC gets tight in the last 3/4" or so of travel.

Your statement about burr removal/polishing possibly making it worse is my biggest concern. That might make the space larger and make it even more difficult for the BC to properly engage the rail. That's why I'd kind of like to find someone who has some experience with these to work with me. I have an idea, of what to do, but am still a little hesitant. What if I bend the rail and break a piece off? How much 'working' can it handle?

[Bang]

I assume this is a folded receiver. If you are detecting abnormal/unwanted tightness in the last 3/4", I'm wondering if someone had that gun in a vice and collapsed the walls in a tad. I'm wondering why tightness forces the carrier to choose another route. You should see some very shiny spots in the offending
tracks, giving clues to the problem. It's the gun, if another CG does the same thing. Rails may be hardened and if so brittle, but i don't know. Since it cannot be safely fired, I guess it's gunsmith time.

[esh21167]

Yes folded/stamped receiver.I did just touch the inside of the folded rail edge with a file and it cut easily, so I wouldn't say it's hardened, but still a little leery of bending them. Some work hardening from stamping and more from me bending them might equal 'snap'.

[mrnyman]

I agree with Bang, yeah overtightening it in vice could cause the reciever to go out of spec, another cause could be poor riveting at the factory, poor riveting can cause the reciever to go out of spec due to the torquing of the reciever upon firing.

Time to get out your calipers and start measuring or let a gunsmith do it for you.

[Bang]

Uh-ohh... I re-read and "assembled kit" finally sunk in

Well...I looked at my Romanian wasr.... removed the cover and pulled the BC back...the first resistance you should feel is the carrier passing over the hammer and pushing the hammer downward slightly. Coming rearwards more, the next is resistance of the spring as it nears coil bind.

The rear trunion stops the rearward travel of the BC. At that location, it is possible to lift it upwards slightly thru the opening, but the rear spring mount (that dovetails into the rear trunion) keeps it from jumping out.

Remove the spring and look at the rear mounting block at the rear of the spring. Turn it over...see that it is hollow?
Now, look at the angled projection at the rear of the BC. That "beak" enters the hollow of the spring block. That is what keeps the carrier from jumping out the takedown opening. I can see where a weak recoil spring might let a BC jump out.

If that beak/block engagement is not there, consider the BC being the wrong one for the rifle. I don't know if there are variations that are incompatible, but it's possible.

Another thought.... is the spring assembled with two long U-shaped connectors visible within the spring? If not, a plain spring could bear upwards inside the carrier, tending to push the carrier upwards.

Meanwhile, I will take some measurements and post then for you to give you some idea of where things should be.

[esh21167]

On my rifle, that is the onliest place where a carrier can leave the rails (because there are no rails at that location). I'm beginning to suspect an incorrect spring or spring length. Working the BC all the way to the rear with the spring installed, it appears the coil bound spring is what stops the rearward travel of the BC and a portion of the carrier remains engaged with the rails. Without the spring installed, the BC can enter the open area (meant for field stripping) and jump upwards.

I'd look for rails that stop too short of the rearward travel allowing the BC to disengage prematurely;

Pull the bolt back against the installed spring and see if the BC is disengaging because the spring is not stopping the BC farther forward where the rails are;

This could be the issue. Someone else recommended a new heavier Wolf spring as the kit spring may have seen a lot of action and could be worn out. I didn't think the carrier should reach the disassembly point with the spring installed, but it does on this rifle. That's when it pops off the rails.

Should the compressed spring restrict carrier travel to keep it on the rails by design? I'll have to look at another AK to see how it looks.

[Bang]

Romania WASR 10/63 measurements.

Face of chamber to front face of rear trunion: 8 inches

Rails (left and right) begin 1-3/16" from face of chamber and are 5- 11/16" to where they taper open for disassembly.

The front-to-rear measurement of the rear carrier field-stripping opening is one inch (from the point where the rails begin to taper and end, to the rear trunion face.

The forward bolt field-strip opening (rails are opened up a bit on each side of the hammer) taper begins at 4 inches from chamber face and continues for 1-1/4", on both left and right rails.

Outside width of the receiver just below the top rails is 1.369, +/- a few thousndths over-all.

Right top rail widths: .184" at widest, a few thousandths less here and there. There is a "lead" at the forward end of the top rail that begins appx 3/32" behind the front trunion and tapers outward to full width in the space of an inch.

The right lower rail is .290" below the upper rail top surface, is 3-7/8" long, is .315" wide including the receiver thickness. The last half inch of the lower rail
is .287" wide including the receiver.

Left top rail widths: Top rail averages .215" wide, begins 1'8" from rear surface of front trunion, has very slight lead at the forward end for a half inch, opened opposite hammer similar to right rail, .155" at slimmest point.

Lower left rail: .285" below top surface of top rail, 3-5/16" long, begins at front trunion, has an inward-extending projection which acts as the ejector.

Distance between top rails (where rails are parallel and do not form any "lead" or field-strip openings or other opening): point at ejector is .983" ,from rear of hammer on back, .975"

I hope you noted that I edited what i wrote about the spring stopping the carrier. Please re-read.