assault rifles can often penetrate thru objects. Which is
desireable sometimes when u dun wan the enemy to have a place to
hide.
When it comes to hostages, u might hit a hostage accidentally if
the bullet flies thru the enemy's body. Thats when subsonic, but
hard hitting rounds like 9mm is prefered.
Choice of weapon also depends on space, how much room to move
around. If its tight, u dun wanna fumble around with an m-16
rite?
if the enemy have body armor, u need a armor piercing weapon like a
rifle, but becos its tight, u cant have a rifle, how? Opt for
BULLPUP rifles, or short rifles eg, M4, or High penetration SMGs
such as the P90.