30 Kills: Tau Sniper Trophy in Uncharted 3: Drake's Deception

The Tau Sniper is a new weapon in the Uncharted arsenal and is everything the Dragon Sniper Rifle is but in a Handgun. You can zoom in to take out distanced targets but again the ammo capacity suffers for it. You will first pick this weapon up during Chapter 12 - Abducted. Once you have worked your way through the area with barges and a number of enemies (the one in which you gain kills for the Land Shark trophy) you board a derelict vessel and climb it's mast before taking cover behind some barrels (the gun sits atop these barrels). There are a couple of places to farm kills with this weapon as follows:

Chapter 12 - Abducted

The first time you get the weapon is ideal. There will be enemies in the distance with laser sighted weapons, plus an RPG guy will join the fray. There are 4 guys to kill, finish off 3 of them and restart the checkpoint. Be careful to take out the RPG guy as soon as he shows up as he can take you out easily before you get a chance to kill the others.

The next best area is pretty much all of Chapter 22 as there are maybe a dozen of these guns available all through the chapter and with 6 bullets in each there's more than enough to spare. Keep one at the ready and wait for any one of the built up areas with enemies and slay them all but one before restarting the checkpoint.