I tried something a little different to disable the gas system of my Norinco, and actually took pictures.
As you can see, I used a very stiff compression spring behind the piston head. The spring ran the length of the gas tube down to the smaller diameter stops it, and you can see that it takes a couple of inches of compression to install the gas tube. You can also see the fitted plug I made to fill the recess in the gas block and plug the gas port. I figured that the powerful spring tension would keep the plug in place and effectively stop the piston rod from any substantial rearward travel. Introducing the "jd SKS Gas Block System".!!
Incredible!! Right? --- WRONG
There must be incredible pressure we're working with here, because after about five shots, my "powerful spring" was collapsed to the point where the action cycled almost as normal. Total failure and back to the drawing board. jd