Havnt really tried a long range shot. I dont see the point.. bullets go exactly where your crosshairs are aiming regardless of range. The longest shot possible is whatever the range the game will draw NPCs/creatures is which depends on the power of your system and restrictions of the game engine itself.
So basically if the NPC didnt immediately disappear from sight when you stepped back it wasnt the longest shot possible.
If you can see it, you can kill it. The games weak draw distance is the biggest limiting factor. Sniping is incredibly easy...no drop, wind, etc to account for. Just put the reticle on your target and squeeze away.
This is true. Distance is one thing. Wind, drop, even the Coriolis effect should be taken into account.
Personally, more than just distance, I always feel satisfied if I can get a one shot kill on a moving target from a distance. And even then, I'm not sure how accurate that really is.