Parts kits are around although not cheap I was just curious if anyone ever attempted a semi auto build of an MP40 in 9MM?

someone made one at one time, doubt it would have passed muster to make it into the US.

http://globalnews.ca/news/525833/525833/

If you really want one bad enough, go buy the real thing.   If you look hard enough, you can probably find a tube gun for $9-10k.

Otherwise you will probably be into a semi auto for at least $2k and it will likely never run right.

I'm sure someone on the weaponsguild has done one. Indianapolis Ordinance sells the semi auto bolt kit that will work for it.

You just have to come up with a semi auto FCG. A sten FCG would probably work fine. My semi auto sten using their bolt works great.

But you are looking at 2.5-3.5 K finished, and that's approaching actual subgun prices....

Indianapolis ordinance vertical feed sten kit, plus dress up and tax stamp.

A place called Schlosser's Shooting Room built about 50 of them ten or 12 years ago. 16" carbine version with folding stock, fixed (folded) stock pistol version, and SBR (I think). They were about $2500 then, and the last two I saw on GB were going for a grand more then that. If I remember right, the Mfg. was a reservist and got called up for active duty and shut the operation down, never to restart it. They were big into making blank firing non-guns for re-enactors, but that ended too. I was THIS CLOSE to knabbing one, but had a new kid and...you know. Now I have to be satisfied with the stupid GSG MP-40 .22lr. WHICH I just submitted a Form 1 for.

Found this:
http://www.guns.com/review/2012/06/18/gun-review-ssr-mp40/

I used to have an SSR40.  It functioned fine although there were some issues that I couldn't tolerate so I sold it.  Fun little gun though.

I was wondering the same thing myself. SS Room was the main place to get them but they're all sold out and out of business. Have you found any parts kits that are complete?