Thanks guys. I have all the information I need re the semi modifications.

The problem is that they (the Americans) re-weld up an old receiver. Up here in Canadaicon we are not legally allowed to do that. In order to have a legal semi only bren, we need to machine a COMPLETELY NEW receiver. As I have access to a CNC machine shop, I believe I can do that.

I have a CAD model (Solid Works) of an Mk II receiver I’ve drawn up based on measurements I’ve taken from a cut up receiver. However my model has two flaws. First actual engineering blue prints used for production will also have tolerances to the measurements. Second as my measurements are taken from a cut up receiver, I can only guess how much material removed during the cutting process.