Bigger IS better!!!
My smoothrifle is .72 cal (12g) I can load it with ball, buck & ball, shot, nails, rocks, small cats...just about anything I can jam down the bore.
I can use it on anything from tree rats to elk, and doves to turkey. The nice thing about smoothbores is that they do not require pure lead. They will shoot WW just fine.
Can't say enough good things about them. :grin:
The only drawback is when shooting patched balls, my 2 1/2" ticking patch looks like a matress flying through the air :-D I usually use just a fiber wad nowdays.