I remember during one of the 15th's COIN ops on Altis [and one of the first operations in ArmA III], a chopper had gone down, and my fire team had been sent to rescue the pilots.
We were in a stand-up, knock-down, drag-out fight against insurgents for at least twenty minutes. I was on the .50cal on the Humvee we drove in until it ran out of ammo, and then I fought with my rifle until the rest of the squad relieved us.
Probably one of the most intense firefights I've ever had in A3, and I racked up more kills in that shootout then I did in my entire MilSim career prior.