Best Sniper possible?

Whats the best possible sniper that can be made in this game? I mean best base sniper, with best synergy for it, and best combo of mods?
From what seen so far, the best combo is a Meteor Bolter with Assassin Synergy, with Electric nano.
Anyone know something better?

i got a purple bolt action with 1369 base damage with a 3.5 crit multi...

the highest ive seen it crit was 14k... normally hits around 8-10 though (( overpower was used on the 14k ))