lmg weapon challenge ghost recon future soldier?

Answer 1

I did this before I reached Paez's hideout with an M60, when the cutscene ends and you see the group of 5 enemy troops converging in the center of the area, move to the left past the barrels to the lone tree. Do this quickly, or one will walk away. All you have to do is pull the trigger and drop all 5 without letting go, do this fast. You will be discovered, but you will maintain the tac-challenge when it forces you to restart to checkpoint.