M24 has pretty much perfect accuracy, but you need to hit the target twice to kill it, and its used just like the L9, so thats out...
SR-25/MSG-90 are decent accuracy, semi automatics... meaning the 2 bullets it takes to kill someone are a bit easier to do.
M39 is great. the accuracy of it seems to be better than what the game tells you that it is.. damage is like MSG-90 but if you can do a really fast double click, both bullets will hit the same spot, or target. this sniper is an automatic, since you can hold down the trigger and it'll keep shooting.