First and second didn't get, third one I saw the barrel end, or something that looks like the end of a barrel but actually isn't, and the last 3 were quite easy to spot.
I spotted 5. But what I was really spotting was something which didn't look quite right and because I had been told there was a sniper there, then that's where s/he must be. If I'd been just walking past I doubt I'd have spotted any of them except the 1st rocks one.