@CountSero@Nutcrusherr- Hit Tier 1 with it the other day("Challenging" 75% frustration and 25% laughs). Yes it seems a headshot from any distance is a one hit. Though with standard rounds/silencer that doesn't seem to be the case. I think standard rounds by itself limits it's 1 shot range even without a silencer.
My advice don't try to solo, it's best to support other team members and then you won't be noticed in time before you blast 2-4 of the other side. I found 4x scopes lines easiest to match up for long distance shots. 6x has a giant red + that makes distance shots harder to adjust for. There is a slight delay between trigger/sound and shot something you'll need time to get use to. The fire rate bonus for standard rounds might suit you at close range, but 9/10 if you don't get a headshot the first time you're dead anyway(G57 pistol on burst is a better option). Positioning is everything or you get punished endlessly.
Edit** Almost forgot with the hit reg issues you're going to occasionally see what should be a headshot but nothing will happen and you're going to likely die before you can get another shot off. Sometimes it happens a few shots in a row... It's sucky!
That's all I can think of for now. Happy hunting!