Montreal is going to learn a hard lesson. If someone is throwing molotovs at your EMTs, the proper response is three-round bursts at the thrower from an M4, not "understanding".
M4s don't have 3 round bursts, just full auto and semi. M16s have burst.
HAH, I'm better at the internet than you!
M4: safe, semi, 3 round burst
M4A1: safe, semi, full auto
M16 & M16A1: safe, semi, full auto
M16A2 & M16A4: safe, semi, 3 round burst
IMO, 3RB is an abomination and whoever thought it up needs a smack upside the head.