Riven

Multishot is very important for Double Tap, so getting a riven with one is very helpful. Otherwise, just serration is fine.

Double Tap

• Double Tap scales multiplicatively with total modded damage, including even faction mods
• Multishot allows Double Tap to ramp up faster, and provides additional damage per burst due to Double Tap counting hits-1 for the bonus of all pellets in a single burst
• Aero set mods increase the duration of Double Tap by 1 second each, making maintaining the buff much more comfortable (rank doesn't matter)
• Primary merciless gets reload speed low enough to maintain [Double Tap] across reloads

Status

With all of the multishot you should be going for, having at least a small status chance bonus from a mod like [Malignant Force] bonus will help give you a few extra status procs since it applies per pellet

Headshots

As a high accuracy marskman rifle, this weapon can rely a lot on headshots. Since critical headshots give an additional 2x multiplier, it is important to get high crit rate with either your riven or a scope mod.

You may also choose Primary Deadhead instead of Merciless, giving higher damage bonuses for headshots. Though you do give up the more comfortable reload, putting you at only 0.6s instead of 1.2s to land a hit and maintain [Double Tap].

Incarnon

Starting in 33.6.9, [Double Tap] functions with incarnon mode, but ONLY increases AoE damage, not the direct hit. If using the weapon in a way that the first hit isn't direct, as only direct hits stack double tap, using something like Hunter Munitions instead for incarnon usage may be best.

EVO II - Riddled Target

Has synergy with [Double Tap], although puncture procs are somewhat rare if modded with elementals. However, Incarnon form provides plenty.

EVO III - Marksman's Hand

-60% recoil will help stabilize the main form greatly, although the Incarnon form doesn't have any recoil.

EVO IV - Critical Parallel

+24% crit chance is insane. Literally over doubles the base crit chance of the weapon. The armor strip perk is also a great alternative, giving the ability to full strip, though again, puncture procs aren't too common unless you are getting a lot of ricochets with Incarnon, and have modded a bit for status.