Only time is use the arty is when ive snuck into the attackers base on harvest day as spec ops after our first base had fallen. Kill the dude with a knife, jump on, wait 30 seconds then fire randomly at base 2 to get his attention jump off and hide, he comes back gets straight back on, gets a knife in the back before he can fire his first salvo, i think this cant possibly work again so fire it, plant c4 on it and run as far into the woods on the left as pos, wach him trudge back on foot and have a real good look around the gun for me, even firing into bushes , gets on the gun, i did let him fire this time befor blowing the c4. (In hindsight that last barrage he fired killed one of my team and two of his so maybe i shouldnt have interupted)