though it gets annoying but i take advantage of spawn campers with proximity mines or with the sniper class to pick them off easily.
If your getting spawn camped by spawn grenades that's really your fault and if your feeling desperate put boost on run out of there and place your own spawn grenade out of the heated area. I just hate cheaters that's all. As for turrets they are way more effective in tight corridors. You'll be lucky to get a kill in an open area unless its a huge map, try putting it in tight corridors.
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