Gunco Forums banner

Gas Piston/Tube combinations and differences

4K views 18 replies 12 participants last post by  Ken3030 
#1 · (Edited)
Build DONE - Gas Piston/Tube combinations and differences

I've been searching for a while now and is there a list of gas tube and piston combinations that work with one another? I am in the process of taking a Maadi AKM and SBRing it with a M92 barrel. Turning down the barrel to fit the rear sight block, gas block and sight are not a problem.

But anyways, initial plan was to take a krink gas piston and use that. But it's way too short to work on a M92 barrel and keep the aesthetics. I can always make the gas tube shorter but I want to have wood on the upper handguard. So then I bought a M92 piston only to find out that it's too big to fit into the gas tube because of the stars. I even went so far as to enlarge the gas tube by heating it up and pressing a 10mm socket through.

A listing of pistons and their measurements would be great. I found a site that had barrel profiles which helped me out tremendously with getting the M92 barrel profiled to work with the Maadi parts.

ETA
Build is finally done, gonna try to media blast and paint it this month.



 
See less See more
2
#2 ·
I don't think there's a list any where, I never seen one.

Guys have shoerten standard tubes to length they wanted, for the hand gaurd retainer they find the spot welds on the front one and move it back, then reweld it and shorten the hand gaurd to fit.

What about taking the "star" off the M92 piston? I never compared mine to a standard piston so I don't know what else is different.

If turning down the barrel isn't an issue, can you make a piston?
Or how about taking a full length piston, cut the head end off, then cut the shaft to length and weld it back together. If welding is an issue, cut the head off then drill/bore into the head and press the shaft in.
 
#3 ·
awhil;e back some of the sites listed the lenghts of the gas tubes they were selling for different variants of ak's, but no two tubes are alike some fit fine others need to be trimmed or traded cause they are too small
I would do a bit more research on the web
 
#4 ·
Also you can cut down the tube as Coils mentioned, to the overall length that you want, and if needed you can also cut the wooden stock pieces to a shorter length as well. I cut one gas tube in the middle and took out what I needed so that when I welded it back, the front handguard retainer was properly lined up with the lower handguard retainer. Then I cut the stock to length and reprofiles so that it looks correct. Hell the gun looks like it came from the factory that way.
 
#5 ·
Here is what I am working with. Basically the M92 piston is the correct length but has the stars on it to keep it straight in the gas tube. So either I make a new tube to accommodate the star, grind down the star or I find or machine a new piston. I've shortened one gas tube, I just need to swage out the end to fit over the gas block. But that will be after I headspace the barrel in the front trunnion.



 
#8 ·
uhm yeah that's it. i'm still looking for lengths and diameter measurements of different gas pistons. i saw the above link, but it does not have piston lengths or diameters listed. it also does not list gas tube diameters.

it does have
- barrel dimensions
- gas tube lengths
- bolts
- bolt carriers

it's similar to this site, but without the drawings.
How to build an AK 47
 
#10 ·
now that i know that the star/carbon scrapers can go, the piston works fine now. just making sure that they are not necessary before i find out that i fubared and need to buy another one!





next step is to cut down the front sight and weld it to the gas block.
 
#13 ·
So we had to cut down the piston a little bit more. Luckily the M92 one I had was soft and we cut, pinned and silver brazed it.



Gas tube has been cut down and flared out to fit as well.


Counterbored the muzzle device so that it sits flush to the modified gas block/front sight. We still need to take down some of the taper so it can be notched to use the index on the front sight.
 
#19 ·
Nice job! Looks good.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top