Really I don't know of any others than the Savage that is over under .22/410.
You could look for a Springfield m6 scout, my grandfather had one and its quite the cool gun. It is an over under .22/410, originally built for the air force to put in the back of seats in case of a crash. The stock holds ammunition, originally the .410 were filled with flares of the same diameter. Problem is 1. They have a very short barrel and are not very accurate at all (compared to a bolt ruger/cz .22), 2. They are completely metal so they get really cold in chilly weather on the hands and, 3. They are quite expensive (800-1500) IF you can even find one.
They do not have a standard trigger, but a squeeze trigger with its pull adjacent to the handle, and they are also really loud.
