Alliant shows a Clay Dot 7/8 oz load in 2 3/4" hulls at 5100 psi. i use it in an old Damascus Charles Daly that somebody installed a long forcing cone 2 3/4" chamber in. Still have all my fingers. I talked to a Hogdon tech guy and he indicated that 2 1/2" shells have a much higher chamber pressure than do 2 3/4" shells with the same powder and charge due to the smaller explosion chamber. Makes one think of lengthening the chamber. Jim Pettengill