SWAT Teams use grenade launcher to dispense tear gas and smoke round..... Im actually being legit whats wrong with a SGT having smoke rounds on his MX which is what constables have?
Edit: or even having it as an addition to SWAT as another class? Acctually why not add two new classes to swat. A sniper class with a .336 and the Grenade launcher ((For those unaware their are three classes for swat already Leader Assaulter and recon, They are randomly assigned when you report for swat duty))