but then he looses the semi-auto only and the robust nature of the gearbox..
i have a systema gearbox that has an m170 in but i know for a fact that this isn't shooting as nicely as my old PSG1 with a 300% spring..
plus durability..
IF you remove all the stock internals with an FTK (and fit it well, the key) then you shouldn't have reliability troubles (unless you really like spamming the trigger and run 500 round mags!)
it's also something special, i actually wish i could buy my old gun back but the owner isn't having it