Prisma Grakata is a good candidate for Primed Plated Round arcane. Increase the mag size, increase max ammo pool, and have some ammo mutation (i.e. carrier). With usual crit and multi shot mods, the rest is up to you. Wild frenzy helps to empty the mag lickety-split, and may refund your ammo with multiple kills, in which some punch through can help with hitting more than one target.
Ignore everything. Argon Scope or Galvanised Scope that shi and go viral dmg. Fwahkin jack up that Critical Damage of that bitch and you're good to go. Trust me bruh I am high on Grakata muzzle fume and gas compensator.
