Gunsmithing AK Questions

[jonaddis84]

Alright, so I dont know if this makes me less Murican or not, but Ive never worked on an AK. I have a customer who apparently had a baffle strike on his SBR AK, so he wants the barrel checked and re-threaded if needed. He says 10 shops in Ohio have turned him down, and doesnt want to ship it out of state I guess since its NFA (even though that doesnt make any difference). But to each his own.

My question. I dont want to get into working on AK's, so I dont want to go out and buy anything. But could I get the barrel off with what Ive got laying around you think? I cant imagine its terribly complicated, but it does sound like the barrels are pressed into the receiver, and also rivets also holding it in maybe?

Thanks in advance

 

[g2gjoe]

The barrels on AK-47s are hydraulically pressed in, once you take one off and try to put it back in, it will be loose or not the same if you know what I mean.

 

[g2gjoe]

I removed the slant break flash suppressor off of a AK once, and replaced it with another style of an AK flash suppressor. I did this because the original slant break flash suppressor was corroded. From shooting corrosive ammo and not cleaning it. When I went out to test fire it, at 50 yards, the bullets were striking about 20 feet from where they were before, and that groups were about 6 feet wide. I thought the barrel was screwed up from being corroded too. Until I noticed copper on the exit hole of the new flash suppressor. So I ordered another replacement slant break flash suppressor, and the rifle returned to normal. Back to minutes of pie plate at 100 yards.
I would suggest the guy go with a larger bore diameter suppressor, like 338 or something.
When I had the rifle in a vice, and had the barrel level, the flash suppressor also showed that it was level. So I don't know if there is a reason that AK's like to kick bullets up, but if this guys threads are true, then this is what's happening with his suppressor.

 

[Kentucky Jelly]

You can do it. Gijoe that may very well be the worst post I have read on here. Congratulations

 

[Kentucky Jelly]

Wow second post is a gem too.

 

[biffj]

As noted above removing the barrel on an AK just to work on it is pretty much a no-go deal. If you pull it you might as well replace it. The retaining pin hole is usually drilled after the barrel is installed. If the barrel moves at all in either direction headspace changes. On the shorty AK's that were originally short barreled the flash-hider or muzzle brake is threaded onto or part of the front sight base and is likely not true to the bore. Fixing it can be done but is a difficult thing.

If the barrel itself is threaded from the factory its likely the threads are off and can easily cause baffle strikes. The threads were never intended to be used with precision suppressors. In fact the whole weapon system works very poorly with suppressors. The gasport is huge and vents at the front end of the gas tube with a lot of noise. In any case, there are those who have to have a can on their toy so you might be better off working with the barrel in place. Chuck it up in a 4 jaw holding the receiver and using range rods true up to the bore. You can thread the barrel somewhat undersized and add a bushing so that you can recut the thread to whatever size you need. This will allow you to avoid changing the length of the barrel if its close to the front sight base.....if its long enough than cut off and rethread.

AK's can be a pain to deal with in this sort of work but can be done if you're careful.


Frank

 

[bptactical]

^^^ the above nails it well.

You never, ever trust the threads on an AK for concentricity, axial alignment or threadform.
I thread them frequently and don't pull the barrels.
I silver solder an oversized bushing, turn it true to bore and thread it.

 

[jonaddis84]

Bp, how do you fixture it with receiver attached? I guess I should just get this thing in my hands, was just trying to decide if it was even worth my time.

Sent from my GS5 on Tapatalk

 

[_DE_]

Just skip it.. Just let the guy pay an AK PLUmber do did it.

 

[bptactical]

Bp, how do you fixture it with receiver attached? I guess I should just get this thing in my hands, was just trying to decide if it was even worth my time.

Sent from my GS5 on Tapatalk

Whut? Give up my secrets?


I took a chunk of steel and milled it so the receiver locks in with the stock tang and a couple of set screws lock against the rear trunnion on the sides. I then turned the back end of the chunk round on the approximate bore centerline and I chuck it in my 4 jaw.
You can't dial in on the chamber but I have had good luck on the barrel just in front of the front trunnion/rear sight brace as an indicating surface. Try to find a machined surface because the barrel finish on most is rougher than a cob.
The muzzle is either supported with a brass spud and live center or the steady rest.
It is not an ideal situation and I have to take light cuts or vibration and chatter is an issue.
If your lathe is large enough you can chuck the receiver directly(I still have to do this on milled receivers).
Protect the sides with heavy copper sheet, brass or aluminum. Make sure to "bridge" the top and bottom with small squares of steel, you can collapse the thin sheet metal on the bottom and your top jaw will hang up in the upper notch on the trunnion preventing you from adjusting side to side plus ding up the trunnion.
When it is dialed in the jaws on the side will roughly be aligned with the top rivet of the rear trunnion.
It's a little sketchy with my 8" chuck but much better with my 10" chuck.
Tape down the rear sight and front hand guard retainer, they will rattle around and make your vibration worse plus ding the finish on the barrel.
It will vibrate no matter what you do, just keep it slow and light cuts.
Sneak up on it.

Good luck and feel free to holler.

 

[xringaccuracy]

Turning AK muzzles for a concentric thread is machining 101. Its a pain but not an issue. Replacing a barrel, I won't touch that, the force used to pin these rattle traps together is immense