I saw a "Carbon" pistol w/ 7.5" barrel advertised in Shotgun News.  Would a .223 do any good from such a short barrel, or would the velocity drop turn it into a .22?  Do they load any rounds specifically for short barrels with quick burning powder?  Are there .223 bullets that fragment at these velocities (which should still be way higher than most handgun velocities)?  What about muzzle blast?

I asked this in a thread someone else started about Carbon 15's, but don't think a lot of people opened the thread.    

I have a Patriot Pistol, 8" barrel. I can tell you that it is not just an ordinary .22. You do lose a lot of velocity with the shorter barrel but not that much. I think the average .22 long rifles are around 900-1100 fps, .223's even out of a short barrel are still around 2400-2600 fps or so. You hear all kinds of contradictory balistics data about .223 speed when it comes to AR pistols. Some people with tell you that the loss in velocity makes the AR pistol a bad choice, while in the same breath brag about the AR-15 rifles ballistics out to 600 yards. ?!?!?  The AR pistol definately has more punch at 100 yards than a 600 yard AR 21" rifle shot. Someone posted the speed of a .223 at 600yards, 1250fps I think.

With an ACOG reflex sight added, I found my pistol to be very accurate up to 100+ yards. I personally feel that my AR pistol is a pretty good home defense gun, small but powerful. None of my other pistols have a 30 to 100 round capacity and can easily hit targets at 100 yards standing shooting freehand. And you definately won't get clothes-lined running around in a tight hallway. It's too bad you aren't allowed to mount a telescopic stock on pistols, that would make them pretty awesome close quarters combat weapon. ;)