Now I know you can make your own Short barrel rifle after getting ATF approval. I have been looking at the Mp5 Clones.
Would it be possible to by one of the ones sold as a pistol and file the paper work/jump though all the hops and put the stock on it or would you have to get the one sold as a rifle and then go from there. I guess my real question is can you turn a pistol into a rifle?

Pistol
http://www.gunbroker.com/Auction/Vie...Item=104268795

Rifle
http://www.gunbroker.com/Auction/Vie...Item=104158521