I was thinking about trying to build a sten froma parts kit.  But have a few questions.

1.  How hard is it?  I see the parts kit, and the 80% receivers....but how hard is it to put them both together?

2.  Are there any 16 inch barrels for sale so I wont have to SBR it.

3.  Can I build it into a pistol so I can avoid the SBR?

the problem with building the pistol is that you need to remove the stock/pistol grip to take it apart, which would allow you to stick a stock on(which means NFA SBR violation).  as for 16" barrels, you could always take some steel tubing, and make a permanent flash hider out of it.  another concern is building the receiver in such a way as to prevent the use of full auto parts, such as putting a rail in the receiver(like the semi uzi) or using a undersized tube and turning your bolt down on a lathe.  then there's the fire control problem.

I've got a mk3 kit that I've been trying to figure out how to build into a semi.  havent really gotten to it yet.  I'm kinda kicking around the idea of using an AR firing pin and some sort of bastardized AK or AR trigger group in a custom bottom end.

look at an uzi type striker firing pin, much simpler than a hammer type

another good idea

btt