Practice is indeed a big part. Great point Lee. Where my point lies is in the importance of using every tool in the toolbox, and using the right tool for the job. Does 00B kill well? Yes. Does it also penetrate walls with the same aplomb? Yes. Does #7 Birdshot fail to stop an opponent as well as it fails to go through walls? Yes. There's alot of rounds between #7 and 00B though, so surely there's a middle ground available. BB shot for example. According to the one test of BB shot I've seen (there's not alot out there) it gets approx 14-16 inches of gelatin penetration while at the same time losing much of it's power after going through 2 sheets of drywall. All of this is at 10-15 yd hall distance. Is it a compromise? Absolutely. But if you live in a world of "no compromises" then why not use a 7.62 rifle for all engagements? Slung over your shoulder for shopping trips.
"A ship is always referred to as she because it costs so much to keep one in paint and powder."
-ADM Chester Nimitz
ETC(SS) Phil McCrackin