"It is extremely dangerous to shoot 2 3/4-inch hulls in a gun chambered for 2 1/2-inch cartridges. The reasons against such a practice cannot be stressed enough."

"First of all, the cartridge itself is too long to fit into the chamber properly, the end result being that the front end of the hull is forced into the chamber cone. This will cause serious rise in pressure, a dangerous factor in itself."

Beyond that, powder and shot charges in 2 3/4-inch cartridges are usually heavier than those used in 2 1/2-inch shells, for which your gun has been proofed. By combining these two factors, you run the risk of building up a higher pressure than your shotgun can withstand, thereby increasing your chances of an accident."

"To be on the safe side, stick with 2 1/2-inch cartridges."...

From the editor of SHOOTING SPORTSMAN magazine Feb/March 1988 page 89.