Originally Posted by tnedator
Using any quality, modern handgun ammunition, ALL of the duty calibers (9mm, .40, .45) will go through multiple layers of dry wall. There is little if any difference in the penetration of .45 vs. 9mm.
Ironically, while the anti-gun people demonize AR15's, the fact is that most 5.56/.223 bullets will penetrate FAR fewer walls than any handgun, which is actually why a lot of SWAT type agencies have gone to AR15's chambered in 9mm, because it will penetrate walls and still penetrate the bad guy.
Unfortunately, there is no good solution to penetration of walls in the house (or leaving the house) with handguns, short of hitting the bad guy you are defending yourself with.
That's why I said "more likely vs less likely"
I have a Sig516 Patrol and agree 100 percent. The AR-15 just looks like a scarier gun.