View Full Version : AK gas piston removal?

10-17-2007, 4:54 PM
I just got a new US made gas piston for my SA85M but I can't seem to get the old one out. It wiggles around but won't unscrew. Is there something special I have to do to get it out?

While I'm asking, how hard is it to replace the trigger assembly? Is it as easy as punching the pins out and replacing parts or does it require special technique to hold all the parts in place as the pins go back in?


10-17-2007, 5:00 PM
i belive there is a pin you have to punch out before you can unscrew the gas piston out, you might have to drill it out, and you have to put in a new one or reuse the old one if u dont drill it out. as for the trigger assy. you need to remove the spring inside that holds the trigger assy. pins, i think its a l shaped spring wire, the pins will come out, then the trigger assy. take note which order you remove things in, to put them back in the same order, if you like, take a picture or video tape how it is now, for referance when you install your new trigger assy. hope this helps.

10-17-2007, 5:18 PM
The gas piston is held in by a rivet. You will have to grind off one side and punch it out, then replace with new rivet that came with your gas piston hopefully. Pay attention to how many turns your gas piston was from bottoming out on the carrier.

The FCG is pretty easy to swap. If it's a Tapco G2 it came with a sleeve that holds the trigger and disconnector together so you can drop them in as one piece, which eliminates having to push the disconnector into position and slip the pin in at the same time (which isn't that hard anyway).

Hammer goes in first, then trigger & disconnector, then hold the trigger down and install the selector.

10-17-2007, 8:07 PM
Cool, thanks for the info. I now see that there is a pin through the thing. I can't tell if it is welded or not as it is very well fitted(I can hardly see it). Is it super critical to count the turns or is a close approximation close enough? Just curious, but I'll be a careful as I can.

I did get Tapco stuff, but the piston did not come with a new pin :(

I also got the double hook trigger so I'll have to modify the frame to get it to replace the single that is in there now.

Maybe I can get Randall to do this for me, it would get done way faster and cleaner!!!

M. Sage
10-19-2007, 10:05 PM
You should be able to get enough compliance parts without changing your piston out... What's your parts count so far?

10-19-2007, 10:18 PM
Yes, M. Sage is right - you shouldn't have to change out your piston - plus it's supposed to be a real PITA! You have to drill a hole in the new one - then run a pin (usually, people use a nail) through there - then you have to peen it into place.

You should be able to get your parts count with a new FCG, muzzle brake, receiver, etc. . . You should need only 5 parts if you don't have a pistol grip - and if you do - just make sure it's a USA part (and that your mag is locked).


10-19-2007, 10:19 PM
changing the piston is a real PITA, and not really worth it IMO..

I can meet the 922R compliance with a receiver, FCG and a follower.
how? simple. no muzzle device or pistol grip for now.
accually, i can have my pistol grip and still be in compliance if i get a BB

10-19-2007, 10:37 PM
So swapping out the receiver is easier than the piston? Isn't the receiver the part with the serial number on it? If so, I don't want to change that, this is a registered AW.

As far as part count goes, I think I'm swapping out 5 foreign parts(FGC and thumbhole stock) for 6 US parts(FGC and the furniture(forearm, pistol grip and stock.) I thought I needed to do the piston as well just to be sure. If not, then all the better!!

This isn't my rifle, but it looks exactly the same:

10-19-2007, 10:46 PM
If you are doing the FCG and the furniture you don't need to mess with the piston, and you can add an imported muzzle device. You will only have 9 evil foreign parts:

muzzle device
mags (3)

10-19-2007, 10:46 PM
edit, nevermind

10-19-2007, 10:51 PM
Sweet! As mine doesn't have a muzzle device nor do I have any plans on adding one, sound like I'm good to go :)

Now I just need to convert the single arm trigger'd receiver to a dual arm without f-ing it up!!!