These next 3 guns are the best in the game: 1. The karbine 2. The shattergun 3. The thunderbolt
1. You get this at the start of the game. Very strong. If you don't have any grenades press LT and it shoots out mini grenades
2. 3rd gun you get(after the handgun). This gun is widely used near the end of the game. LT attack can kill anyone at close range
3. 5th gun(after the echo rifle). One shot kill. Zoom. Very useful against the shielded guards(stop time and fire).
You should have these guns through the whole game. Others such as the handgun and echo rifle are to be kept for a little time and swapped for the better guns(swap the handgun for the echo rifle and the echo rifle for the thunderbolt) The bloodhound(rocket launcher) and the surge gun should be used on special occasions The e.m.f.cannon and the hell-fire are not used in the game(unless you want to have fun and mess around