Well in the interest of KISS (keep it simple stupid) what if I went with Boots' suggestion, and just shortened a 223 die, and short reamed a chamber? Make my own cartridge. Besides there is so much 223 brass floating around this country, the conversion would be even simpliler.

That way,I would have a true .378 base and the same shoulder as a 223. I do not need the extra case capacity of the TCM.


Is there something else I am missing here? Would that work? Heck I might even be able to ream the chamber myself, MIGHT., if it were a prethreaded barrel (I cant do threads).