Shotgun actions for DR build ?

I have a couple of actions that i am thinking of converting to DR, but first need to ask if somebody can suggest if my choice of Caliber is OK ? Actions are Older AYA 20 gauge Magnum, ejectors, and BAYARD Hammer double 16 gauge, Greener crossbolt, backlocks, for conv. to 45LC cartridge. AYA is Hammerless, bushed f-pins for rimmed cartridge.What cartridge would that one be best suited for ? Both shotguns are tight on face.