my sks jams when I try to fire more then one round I don't know why I check the gas value gas tube and yes check to make sure the grenade launcher is off
are you using the factory 10 round mag or a afetrmarket magazine?
I'm using the factory 10 round mag
I had that problem with my russian, I had to replace the firing pin case/housing unit and it worked fine... but it could be due to many things such as the mag (like greasy was getting at), feed ramp etc...
it could be the bolt is plugged with cosmoline.disassemble and clean the hell out of it with brake kleen.
righttobarearms, more information is needed to help with your SKS jamming problem. Besides the magazine question already asked, how is it jamming? Is it ejecting the spent case or jamming on it? Is it failing to load the next round from the magazine? Is it ejecting the spent case and loading the next round but the hammer isn't cocking? There could be a host of things that will cause this problem but without more information from you everything is just being guessed at. The first thing you should do to a firearm with a problem is follow the smithing #1 golden rule, make sure the firearm isn't loaded, then do #2 a complete disassembly and cleaning of the firearm. Look for broken or worn parts. Reassemble and test fire. After you've done this, if you still have the same problem repost here with all your information to the questions asked above and we'll see if we can't get you a fix for your problem.
Scarecrow hit the nail on the head.