Just take out the piston.
That's what I was thinking...but doesn't it snort fire/smoke out of the gas tube vent holes? I suppose you could always leave the piston in place and just use an NC Star gas tube...those suckers don't hold enough pressure to move the piston anyway....and it leaks further away from your hand.
I wonder how much velocity could be gained by not bleeding off that pressure. In theory, shouldn't it tighten the groups a bit at normal ranges a bit?
It would be interesting to tap the inside of a gas block, so you could switch between straight pull and semi by installing or removing a plug. If anyone wants to try doing that and feels so inclined...I will donate a couple of Russian gas blocks for the cause...it would be cool to see if it can be done while keeping it outwardly appearing intact...if the plug can be slotted for a flathead, perhaps the plug and an AK screwdriver in the cleaning kit for the ability to switch...'in the field'.
This could actually be considered applied research into what could be done to keep our beloved SKSs should they ban semi autos someday. Perhaps if we get ahead of them, and come up with a way to not totally butcher them as we have seen done by Canafornia type governments we might be better off? At the same time, my gas blocks will skyrocket in value. Perhaps I should shut up and not give them any ideas?