In the past, I chopped some STEN mags down to a 10 round capacity & shipped the parts to be welded to the correct length by someone in Connecticut for their STEN build.

Someone on another board from California is now asking me to chop some STEN mags for him.  Under your previous legislation, I could see how this would be worthwhile.

Under your new regime, certain guns, like the AR & the KelTec SUB-2000 lend themselves to compliance.  With a fixed single feed magazine, I'm not understanding how he'd be able to reload his STEN.

As I'm not taking any money for the work, I'd like to know if there's a legal and workable configuration he can build to before I break out the Dremel and start cutting.

Pistol grips are one of the main features of "assault weapons" in California. So an AR, AK, FAL, Keltec 2000, etc pistol conversions run afoul of our AW laws. A STEN using the tube stock has no features prohibited and as such can use a removable magazine. The only legal concern at that point is magazine capacity.

So a semi-auto STEN carbine with a 16" barrel and no other prohibited features would be legal in this state and could use a removable magazine that has been permanently modified to hold 10 or less cartridges.

Ah, ok, that's huge.  So under the new anti-2nd Amendment language, they forgot about STENs, as long as they don't have a pistol grip or thumbhole stock?  Excellent.  Perhaps we can proceed.

I have a semi auto STEN MkII and it's just another "featureless" rifle.  16" barrel, over 30", no flash hider, no pistol grip, etc.  If I remove the stock and put the optional STEN pistol grip on it's an assault weapon. 

And yeah,  I have to convert a box of STEN mags to 10 rds.  Or not.

If you need moar, ship em to me and I'll chop em for ya.