For sure break it into small blocks of action, but maybe you can get a few kills in with dialogue too.
Depending on the type of campsite you mean, (like if it was a military kind of situation.) there could be some announcements over a PA, orders being given, guards talking or a guard watching a TV and reacting to it.
If it is in the woods (camping kind of site) ,the protagonist can creep up and quietly take out someone off having a leak that is drunk and singing.
There could be people playing cards and drinking that the protag is creeping around watching.
There could be someone telling a fireside story to the group, then when the story peaks the protag springs out of the shadows bullets flying, or when the story peaks a bullet hole appears in the story tellers head, and the battle is on.
If they are all sleeping the protag can be creeping up and suddenly from within one of the tents a cell rings and the protag freezes and steps into the shadows, someone exits the tent speaking on the phone and trying to get better reception, the protag steps from the shadows, snaps their neck and grabs the phone in one swift movement, then awkwardly whispers into it “Uhh, he’ll have to call you back.”, then from behind him “Hey!”, protag whirls around and throws the phone at that person, and the bullets start to fly.
After that you could use people shouting out orders to locate the protag, or yelling for him to come out as he picks them off one by one.
-Thanks-