The lugged area on both of my receiver chunks were cut so that even if I cleaned them up about 1/4" on the bottem would be hanging out. I know what you mean about building another one. I still have a sten build and I am contemplating building another version of this one first. I don't like the idea of pinning the barrel to the barrel bushing. I think I will just thread the barrel to the bushing. To keep the barrel from spinning either weld the flange area of the barrel to the bushing, or mill out a key slot in the barrel bushing. I suspect though if I weld the shroud to the barrel bushing (leaving the stepped flange area of the barrel) that would hold the barrel tight enough so that no other means would be needed. Isn't a sten MKIII barrel held in a similar fashion with the front and rear barrel trunion?