I've just acquired a 12 ga. Husqvarna underlever. I think it is 2 1/2". I could use Magtech brass shells, or roll-crimped plastic. I have a Lyman roll crimp set on the way.
I don't imagine loads are much different than 2 3/4" loads, as the extra 1/4" is just there to allow for the star crimp. Am I right? My gunmaker has offered to re-chamber it to 2 3/4", relieving the forcing cones in the bargain.
PS: 25 Feb 07; Lars returned my PM to say don't rechamber, or fool around with the forcing cones.