This is my standard build for eidolon hunts. Some viable alternatives to the riven are [Argon Scope], [Heavy Caliber], [Primed Chamber] or [Primed Cryo Rounds]. My top recommendation would be to use [Critical Delay] instead of [Point Strike], add fire rate in the riven slot and keep [Vigilante Armaments]. Of course if you have [Primed Chamber], you can use that instead of fire rate. If the recoil doesn't bother you, feel free to replace [Stabilizer] with either [Vigilante Supplies] or [Ammo Drum]. When hunting with [Volt] I'd suggest replacing [Stormbringer] with [Primed Chamber] if you have it. Make sure your [Volt] build is running [Shock Trooper] if you do that.

Note: Fractalized Reset is really the only arcane that makes sense with this build for eidolon hunts since you aren't really killing much to keep up the buff from other options.

Here are the other builds I use to complete my eidolon loadout.

Volt - https://overframe.gg/build/38519/
Redeemer Prime - https://overframe.gg/build/113413/
Wyrm Prime - https://overframe.gg/build/113395/
Itzal - https://overframe.gg/build/113418/