COTW-6 gives base diameter of original rounds as .562"
Should be able to get away with using .348 Winchester brass, just expanding the mouths, FL size.
For better life, use an O-ring or pony-tail rubber around the base on the FIRST firing.
Brass will expand to fit your chamber perfectly.... and it will do it concentrically: no weak side.
Good luck.
BTW, Jamieson will set you back 3 to 4 times the price of .348 and offers no real advantage. I'm cheap.



























