I found the Federal 2 3/4" 1 ounce #6 loads patterned very nicely in my 1900 Husky SxS, with modified choke, left barrel, straight rifled right barrel.
It was actually chambered 2 5/8" & did not mind the 1/16" longer standard 2 3/4" ammo(slightly shorter than 2 3/4"cases actually).