I've run 180's in my '06 Super Improved (Gibbs) to 3,050 in a 25.5" tube. Primer pockets give out fast even at 3k fps. 2,950 is tops for me now. ...
As I recall reading, Rocky Gibbs discovered the same problem, and did consideralble experimentation trying to find cases that would stand the pressures he wanted to run. He finally settled on WWII military DEN43 cases.
--Bob
