I see all of the most long-ranged snipers seem to love the SRR but I dunno why, maybe bullet drop... The original rifle is just as good as the SRR on Hardcore mode, so there's got to be some reason they use it. GOL Magnum is super hard to get all of those kills in a single match, I've tried a few times and failed.
I have like so much else unlocked, though!