You always get the odd bunch of guys who spray the fuck out of everything, it happens.
Some people just have an itchy trigger finger.
Depending on the amount of guys playing, 1,000 rounds usually does me and I always use semi. It's all based on the player.
Sure some ballers have the mindset to spray the fuck out of anything that moves, I've seen it and then I've seen the easy goers who shoot less.