The Cernos Prime introduces a new kind of weapon playstyle with its arrow-fan mechanic. Its arrows are shot side-by-side, angled so that the pattern spreads outward during flight.
You don’t snipe single enemies with this bow. Instead, you snipe -groups- of enemies. If aimed correctly, you’ll get a row of headshots on crowds when shot from far enough away, letting the pattern fan out enough. Learn what distance you find comfortable for unloading the entire pattern into one enemy, and the distance you need to snipe groups of enemies effectively.
Accuracy mods currently don’t affect the Cernos Prime, which could have something to do with the unique way it handles multishot (adding more arrows side-by-side instead of in a cone like normal weapons). Therefore, Heavy Caliber doesn’t make increase the pattern’s spread (although it would be nice if it did).
If you don’t have Pummel or Primed Cryo Rounds, you can replace them with other elemental mods, replacing the D polarity with a — if needed.