I've got a 12gauge 870 loaded with Remington 20636 3" magnum 00 Buck. 15 x 8.4mm balls x 1225fps.
Sure it'll kick and be loud, but I'll be so jacked up on adrenaline I won't even care. Even if I miss the concussion and resulting chaos will be terrifying.
Check out this article and choose for yourself.
http://theboxotruth.com/docs/bot3_2.htm
btw, shooting 3" mags at the range are a BLAST!!! HAH!