Re hull length in shorter chambers and resulting pressure increases . . . In one case, Bell got a pressure increase of almost 1,500 psi. But that resulted from a 3" shell being fired in a 2 1/2" chamber. I'd guess that those instances in which extreme constriction takes place, apparently due to very short forcing cones and hulls that are too long--resulting in ends blown off the shells and wicked recoil--there might be similar pressure increases.