[Diab0l0s]

with what kam just said, but also consider the Unreal engine and what it is capable of and what the community now expects we know its using the unreal engine ie UT2k4

So my guess would be they would try and make it like a dulled down version of UT weapons. Now im not a real coder but ive got some experiance. They could also reduce lag by when player 1 aims at player 2 and player2&3 aim at player 1 that it will onyl calculate and narrow infomation down to those players and an AoE that might come about in the local enviroment.

Then you ask what if another player targets player 1,2,3. Well then this would register on the server and calculate between player 4 and their target/s

But then there is also the Graphics lag of bullets, smoke (RPG) and wateva else. Well my thought on that is that the game will default option of only rendering say 300 bullets (im just throwing that out there no real number) but still calculate the other 400 which are aimed at you or in the general direction.