A carbine simply has WAY to much over penetration for HD. A 30-06 round wil go untill the curvature of the earth stops it or it hits little sally smith 2 blocks down, and that probably wont stop it either. A shotgun is ideal, I have had to choose between a SG and a SMG for urban barricaded entry(like HD but in reverse
) and I chose the SG everytime. I shotgun can fire 15 rounds at once, of nearly the same caliber of a subgun and can do so 6-7 times. As far a hostage shot keep a low-recoil rifled slug it the side carrier for that sitution, they are very accurate, more so than a pistol round, and they will not go 5000m before they stop. Frangible ammo is also often not effective, leave a very nasty but not man stopping 2-3in deep "crater" in the impact area but not hitting vital organs. Also, FYI, NEVER, EVER
, use any non-slug/sabot SG in a hostage situation! The reason being not matter how tight your pattern, how close you are, or how good you are, that wad will fly wherever it wants to, it is NOT skill dependent!