I'm looking to build a character as close to RAW geared around becoming a long ranged sniper who deals damage from the furthest safest distance. I've been looking at features from ranger/familiar that allow a PC to look through their companion's vision for line of sight, but is there a way to make actually attacking from this distance effective?
Constraints:
Attack must be made with a weapon. The weapon can be effected by a spell or enchanted, if it's a class spell or feature, but the instrument should be some simple or martial weapon at it's base.
Exclude any outside influence from other PCs or magic items that aren't inherent to the class.
PC would be at level 6. It would be interesting to learn how the range/class optimization changes with an increase in level though.
UA would be fine but I know it's trickier to balance multiclassing with.
For effectiveness, the attack should be made without being at a disadvantage if possible.
Any feats/spells, but excluding magic items.