If you want a semi-auto (though I would still recommend a t/c encore or good wheel gun) you can get a Glock 20 in 10mm. They sell a hunting barrel that replaces the factory barrel. The hunting barrel is 6" long.

You can then handload some good 10mm loads or buy some from double tap ammo. Double tap sells a 180 XTP-JHP at 1350 fps and 728 ft pounds.....

http://www.doubletapammo.com/php/cat...roducts_id=122