SWAT 3: Close Quarters Battle (also known as SWAT3 or SWAT3:CQB) is a tactical squad-based first-person shooter, developed by Sierra Northwest and published by Sierra Entertainment for Windows-based PCs on November 23, 1999. It is the seventh installment of the long-running Police Quest and SWAT series.
This is an weapon mod by Robert Martin, It's StoNeR's Colt M4 with an attached M203 grenade launcher, This weapon can be used in Co-Op and in deathmatch as well. This file is not by me and I don't take credit for it either, This file came from Swat3reunited.com
To run the mod, Drag the file to the swat 3 mods folder, Open up the swat 3 mods launcher and check the file, This will activate it in game for use.