SKS Gas Piston Question (update)

[Gutz]

Had cycling problems at range yesterday. This is the second time I've shot the gun. First time ran flawlessly. Yesterday, went through about twenty rounds, then FTF's occurred (all the same ammo was used, Tula 122 gr FMJ). It started acting like a bolt gun, firing after I manually cycled the bolt. I did notice the bolt was very hard to pull back, but when I cycled it, the round in the chamber was properly extracted. The primers on the FTF's were dimpled. I have not checked the headspace, but did notice that the bolt lug locks properly in place when closed. Bolt and carrier are matching numbers. Bolt has been stripped and cleaned. Firing pin rattles freely.

Anyway, got home, took rifle apart, noticed how sticky the piston was, thought I'd start with that. The rifle chambers and extracts rounds smoothly by hand. Any trouble-shooting suggestions would be greatly appreciated. Thanks!

Note, put the rounds with dimpled primers in my Saiga and shot them no problem. So they weren't bad rounds.

Wonder if you had a bunch of "weak" rounds that kept it from a proper cycle???

Have you tried different brands of ammo?

[knucklehead0202]

may have a weak spring or there could be cosmo in the firing pin hole, not allowing it to hit properly, which could lead to it slam-firing too. pull it down and clean the whole MF thoroughly! then see what she does...

[DirtyRussianAmmo]

may have a weak spring or there could be cosmo in the firing pin hole, not allowing it to hit properly, which could lead to it slam-firing too. pull it down and clean the whole MF thoroughly! then see what she does...

The bolt has been stripped down to the extractor spring. There is zero cosmo in/on the bolt. Firing pin and hole have both been sanitized. Firing pin is lubed, and is one rattling mofo. I polished the piston with some wet and dry and it now moves freely in the tube. Gonna start with that. If that doesn't solve the problem, will move to springs, firing pin, headspace. Thanks for the input!

[Crusader]

I bought a ChiCom Type 56 a while back that had the same problem, except that the piston was basically locked up in the tube. I let is soak in a combination of hot water with dish soap and then Hoppes #9 until I could pull the piston out.
Once out, I very lightly sanded round edges of the piston to smooth them up, then finished up with a box of scotch bright pads. I also took a 20 guage bronze bore brush to the inside of the tube to break up whatever rust/crap had built up

[DirtyRussianAmmo]

After polishing the gas piston and getting it to free-float in the tube, took the SKS to the range today. Problem solved! Put 75 flawless rounds down the pipe.
I was on and OFF the black at 100 yards. Here's a pic of 50 yards, iron sights, Tula 122gr FMJ. I know, 50 yards, no big deal, but for my third time out with the rifle I was pleased. I sort of worked my way to the center

[/URL]

I heart my SKS.

[stitchnicklas]

carbon build will also cause stickyness

[knucklehead0202]

beautiful! you'll get the hang of it. I've chased bowling pins and all kinds of other bs around with my SKS. once you're dialed in, the SKS will be your go-to rifle, the one you can pick up and go "yeah, I can hit that". I have a bunch of rifles, some of which I can shoot pretty well, but the SKS is always the one I can pick up and hit things with straight away. they are just great!

[DirtyRussianAmmo]

beautiful! you'll get the hang of it. I've chased bowling pins and all kinds of other bs around with my SKS. once you're dialed in, the SKS will be your go-to rifle, the one you can pick up and go "yeah, I can hit that". I have a bunch of rifles, some of which I can shoot pretty well, but the SKS is always the one I can pick up and hit things with straight away. they are just great!

This is my first SKS, won't be the last.

[knucklehead0202]

it is a slippery slope. even if you have a real nice SKS, you'll see another one and go "man, I really want it" even though they're pretty much all the same. like lay's potato chips I guess.

[Crusader]

DirtyRussian, my bit of advice will be to ditch the Tula and buy Golden Tiger. The stuff is much more consistent, and I went from about a 16" group at 100 yards with Tula to a 3" group with Golden Tiger on a good set of strings.

[DirtyRussianAmmo]

DirtyRussian, my bit of advice will be to ditch the Tula and buy Golden Tiger. The stuff is much more consistent, and I went from about a 16" group at 100 yards with Tula to a 3" group with Golden Tiger on a good set of strings.

Thanks for the tip. Will have to try some.

[kygen]

what would be the best way to polish up the piston head?

[knucklehead0202]

if it's got any rust or pitting on it I'd douche it in kroil then maybe go over it with a brass brush on the dremel. otherwise, just use a buffing wheel on the dremel and some buffing compound. when I got my vz-58 the piston was rusted in it. after 2 days of soaking in kroil I got it out then polished it up. haven't shot it yet but everything moves like it should.