Gas piston replacement

[dagast2 0]

I'm thinking about doing a gas piston replacement as one of my compliance parts since it seems fairly cheap and by the looks of the part, simple.

 

However, I can only assume that its not as simple as I think it is. The piston itself appears to be a steel rod with a threaded end...is the installation more complicated than unscrewing the current piston and screwing in new piston?

 

Any advice appreciated,

Thanks!

[jgillaspy 24]

I'm thinking about doing a gas piston replacement as one of my compliance parts since it seems fairly cheap and by the looks of the part, simple.

 

However, I can only assume that its not as simple as I think it is. The piston itself appears to be a steel rod with a threaded end...is the installation more complicated than unscrewing the current piston and screwing in new piston?

 

Any advice appreciated,

Thanks!

 

 

You have to drive out a pin (brass punch and a hammer). Then you unscrew the piston and replace it, then re-pin it. I've not done it, but I've readthat the pin is a RPITA.

Edited February 8, 2007 by Ax-Man

[Bad Bob 0]

I'm thinking about doing a gas piston replacement as one of my compliance parts since it seems fairly cheap and by the looks of the part, simple.

 

However, I can only assume that its not as simple as I think it is. The piston itself appears to be a steel rod with a threaded end...is the installation more complicated than unscrewing the current piston and screwing in new piston?

 

Any advice appreciated,

Thanks!

 

 

You have to drive out a pin (brass punch and a hammer). Then you unscrew the piston and replace it, then re-pin it. I've not done it, but I've readthat the pin is a RPITA.

Now, let me say up front that I'm not wanting to be 'the blind leading the blind,' because I have never, ever replaced a Saiga piston. But it seems like I've read that military AKs have the piston pinned in place (you can just barely see the pin on some of the piston/carrier assemblies), but the Saigas just have it 'staked' (the surrounding metal driven in with a punch) in place. My Saiga has a couple of 'craters' punched into the carrier, about where you might expect to find the pin in a military AK. If there's no pin, it sounds like an easier operation: drill out the punched indentations, unscrew the old piston, and screw in the new one. I believe someone posted here that they just used red Locktite to keep the new piston from going anywhere (although drilling the new piston for a pin sounds like a more mil-spec approach).

 

Anyone care to contribute, who has actually 'done the deed?'

 

If I'm wrong, I've got no problem at all with anyone saying so (if you call me a "cotton-pickin' fool idiot," it wouldn't be the first time for me ;>). Like most of the other folks here, I'm here to learn...

 

;>)

[getitat 609]

Hello

Well, I tried. I dremmelled out the "dimples" with a carbide burr bit, well through the bolt carrier and into the piston. Chucked up the piston in my bench vise, and did my damndest to unscrew it to no avail. I was afraid I would break the bolt carrier, since the charging lever was the only real thing to get ahold of.

I gave up when it turned approx. 1/8th of a turn and froze, I reckoned it was galled or something. and even if I got it out, I'd have hell keeping the new Tapco in, with buggered-up threads. So, I gave up. I didn't really need the compliance part, I just figured I'd do all I could easily get to, so I would have no worries in the future.

This was on a late model RAA 16" .308, the model with the "Thumbhole/Sniper" type factory stock. I think it was manufactured in 2006.

 

Hope this helps......

 

Respectfully posted,

Guido2 in Houston

[Bad Bob 0]

Come on folks: somebody has to have actually swapped out one of these puppies! What's the best way to get it done? I don't know if the .308s are different than the .223s - that might be important, also.

 

Any input?

[texlurch 0]

I did one on my 21" Saiganov. I used to drill and punch on regular AK's, but it is a pain. Now I drill enough to get into the piston from both sides, then twist it out with the old pin in it. Install new piston, drill thru for a rivet or nail, smash and go. Some are tighter than others, but they all come out.

 

I have done a bunch of standard AK's. Some I pinned, some I punched both sides to peen and loctited. None have worked loose so far.

[ArcFault 4]

Bad Bob is right, it is staked and it is a pain. The thing that makes it really suck is that you have to remove more material than you might think because the carrier and piston are deformed in a wider circle than just the diameter of the dimple. If you dont remove enough, it wont budge, or the carrier will act as a die and remove some of the material from the threads, both on the old and new piston.

 

So... your concerns were justified Guido. I think it is a good part to change out if you are up to it though. One less part to worry about later. Just remove a little more material and drop some oil into the holes and keep working it back and forth as if it were a die, you will get it out. Be patient and dont freak. I used locktite on my .223 and it hasnt loosened up after several hundred rounds, not the most rigorous test but, hey. If you are really concerned then do as texlurch suggested and add a new pin or restake it.

 

Also, you may notice that the new piston is longer than the old. This doesnt seem to matter much but I know that myself and others have shortened the carrier by the difference to accommadate it. The only real advantage I could see to this was that it got me more thread engagement behind the holes with the new piston. This strikes me as a potential weak spot, but on the other hand I cant imagine it ever breaking as the only real force on the carrier is compressive.

 

Well good luck, its really not to big of a deal, just a royal PITA.