Didn't see anyone mention that 2 3/4" loads are for folded crimping and 2 1/2" are intended to be roll crimped. Ergo, 2 3/4" loads should fit into a 2 1/2" roll crimped hull without appreciable change in ballistics. But, with a light, low pressure load, there should be no issue in using 2 3/4" hulls in a 2 1/2" chambered gun. So sayth many sources.

DDA