Yeah, for the moment Bertram Brass is the simplest choice for now & I haven't used any Bertram sticks of Brass that didn't already have a hairline crack.

There are several European vendors where sticks of brass could be acquired, the issue is just getting it shipped to the U.S. of A.

But I have been in contact with the small firm of Rocky Mountain Cartridge Company & they do actually list 6,6X70R as one of their staples:
https://mail.rockymountaincartridge.com/index.htm

Too, in my conversations w/ Rocky Mountain Cartridge Company, they said their sticks of Brass would be stronger than Bertrams but with just a couple folks and they have had some power issues, so they are months behind; but will get to making more. They gave that they would anneal to my requests or needs.

So any avenue is not an easy path @ the moment but as always the >>Glory is in the Struggle.<<

I thought about obtaining some >>Tempilaq<< just to see what temp I could safely achieve.

My Parachute Option is just to drop by Ford's House & let the Master Annealer temper a few.....


Hochachtungsvoll,

Raimey
rse