Why does my sks jam?


July 29, 2006, 11:26 PM
I have a yugo sks that I bought for 160.00 at a gun show last weakend. It appears to be in reletively good condition. From what knowledge I have the gas chamber looks good and is clean, but when you shoot it the bolt only goes half way back and rechambers the spent round and than the bolt will only open about a quarter of an inch so you have to pry the bolt open with a screwdriver. Has anyone had this problem?

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July 29, 2006, 11:31 PM
clean it til your fingers bleed.I bet you'll love it after that.

Car Knocker
July 29, 2006, 11:53 PM
Checked the gas valve yet?

July 30, 2006, 12:11 AM
We had that exact problem with the m59/66 SKS I got my dad for Fathers' Day.
We pulled out the gas valve, wrapped a section of paperclip around the neck so that there is a better seal between the neck and part it sits into, and reinstalled it.
The rifle has worked perfectly ever since then.


This is where I read about this fix.
Hope it helps. :)

July 30, 2006, 12:13 AM
I did thoroughly clean the gun and dissmantled numerous times. As for the gas valve what should you look for to determine if it is bad? Visually it looks good.

July 30, 2006, 02:05 AM
New valve

July 30, 2006, 02:15 AM
That valve is only one part of a larger system, which may have numerous small leaks that lead to a lack of pressure for cycling, due to lack of cleaning after use of corrossive ammo. It's also the easiest one to fix, with a piece of wire, and it really is the place to start.
Buying a new valve is really a second string option, as it's pretty expensive compared even to the rifle.

July 30, 2006, 08:32 AM
http://www.cncwarrior.com/sksparts.asp Cheap brand new gas valves. Mark

July 30, 2006, 10:15 AM
Make sure the chamber isn't pitted do to corrosion.

July 30, 2006, 04:02 PM
If you are using anything other than the stock fixed 10-round magazine, that is likely where the problem lies.

July 30, 2006, 04:42 PM
Buying a new valve is really a second string option, as it's pretty expensive compared even to the rifle.

Used to be. Now you can get them for well under $20. Those stainless steel ones that are being sold are rather nice. They create a really nice fit that fixes any leak problems and worth getting if thats what the problem is. The cheapest I seen valves go for was about $12. My last one I bought was from Heddonpal's Gun Parts for $15 for the valve, spring and switch. Great parts.

July 30, 2006, 07:57 PM
If you got a YUGO 59/66 which flooded the market with very nice almost new condition with grenade launcher feature the gas valve has a single shot setting to be used in grenade launching...your valve is just set to the wrong posiiton


July 30, 2006, 09:20 PM
2nd yodar. Make sure the gas valve is in the right position before you assume it is damaged. The grenade sight should be locked down by the button/switch. If you can raise the grenade sight, you need to switch the gas valve button over to the right.

July 31, 2006, 12:25 AM
Assuming the gas valve is in the right position, there is an easy way to see if it's bleeding off excessive gas or leaking.

Wet a paper towel, squish it up and wrap it around the gas valve seal and shoot a round. See where (if at all) it blows out and you'll know if its leaking.

If it is, you can make a seal like mentioned above. I did it by cutting a 1/16" off the end of a .45 shell's brass (to make a ring), heated it up using a torch until red and glowing, then quench in water. This will make the brass very plyable. Then, you can stretch it over the gas valve and it will make a very effective "gasket" to seal up the area without blowing out.

Works like a charm.

July 31, 2006, 01:46 PM
Make sure the recoil spring is in the right way. The curly half goes into the bolt carrier. If it's backwords it'll cause the bolt carrier to hang up.

Carl N. Brown
July 31, 2006, 03:31 PM
Yugo SKSs are shipped packed with cosmoline.

Cean the gas piston, spring and cyclinder and leave them dry.
Oil and cosmoline in gas systens bakes into a varnish. Jam maker.

Also, the bolt and carrier may still be packed with cosmoline.

THR > Social Situations > General Gun Discussions
> Anyone Know how to get Cosmoline off?

Getting cosmoline off is a great way to spend a snowed-on weekend.
It requires a stiff wire brush, kerosene and a roll of paper towels.

January 3, 2009, 03:11 PM
I have a yugo SKS but has no gas valve, and jamms with every other shot, can someone help?

January 3, 2009, 03:30 PM
If you don't have a gas valve, you have an M59. If its jamming every other shot, you should:

1. Completely disassemble the piston assembly and thoroughly clean all springs and parts,

2. Disassemble the recoil spring assembly and clean the spring and guide rod,

3. Scrub the chamber and scrub the interior of the magazine.

If you had cosmoline on it before, boil all of the parts for an hour. Even if you've soak them in kerosene, baked them, ect, you will still find the gook coming out when you boil the parts.

A word of advice, boil them when the wife isn't home...or at least don't use a good pot.

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