It's not worth it. Economy of scale, especially at S&W means/requires that you must produce or manufacture enough units to make the whole process worth it. One or two or a hundred barrels in one caliber is not enough. Good luck with that.
The Harper Conservatives had 6 years to repeal & replace the dreadful Liberal dreck known as Bill C-68. No one including the NFA or the CSSA has the guts to challenge the illegal & unconstitutional "grandfathering" provisions of Bill C68!!!
Kannada is lost to the socialist Liberals. Get out while you can...