looks like all those reply posts got eaten? anyhow I've decided not to do a tiny RPK with this build. I can't scare up the GB, FSB, bipod and RSB at a reasonable price, and I'm leaning in a different direction now anyway. I'm trying to wrangle up a Yugo gasblock with the gas cutoff, so I can tune the rifle to fire regular 85 grain 7.62x25mm ammo in semi auto mode, or switch the gas off and fire heavy 150 gr. subsonic loads with a manual action. I'm going for about a 3" gas piston and a very short gas system with a regular akm size gasport. what I can't decide now is wether to weld the front sight post to the gasblock for a short sight raidus or to put the FSB all the way at the end of the 18" barrel, which will look odd with such a short gas system.