As a former Australian army sniper I get ticked off when people use the term sniper rifle because a sniper is someone who is highly trained and gone though a difficult course to earn the term sniper...
A sniper can be anyone sniping at you. You don't have to have grand training to be a sniper. There are trained people who have the title of sniper, but anyone can snipe and be considered a sniper. It is a regular occurrence for NATO forces to report a "sniper" anytime being fired on from a position of concealment. So even an untrained Taliban fighter with an AK47 can snipe.
Remember, the origin of the word pertains to being able to "hunt" snipes.
Sniper rifle or hunter rifle - marketing. Funny how lots of "sniper" rifles used by the military have been nothing more than hunting rifles applied in warfare.