If it is available, a Mossberg Shockwave (or the above-mentioned 500 with an adapter) with the 1.75 inch shells should be among the options. You can get 8-9 birdshot, buckshot or slugs in one. The recoil is minimal with the short shells. However, precise aiming is optional except for the slugs. Ammo is maybe a little more expensive than 9mm SD loads, but practice would be a little less IMO.