Despite the appearance of its shots, the Dual Decurion is a hitscan weapon by default.
Starting from Update 27, all hitscan Archwing weapons are converted to projectile when in space. Such weapons (Dual Decurion included) still retain their hitscan properties while deployed in ground missions with an Archgun Deployer.
The Dual Decurion's smaller magazine makes it easy to run out of ammo in a gunfight, but its quick ammo recharge balances this out.
A good way to maintain ammunition supply is to fire in bursts of 2-8 bullets.
Its component parts are listed in Offerings as "Decurion" parts, and Dual is not in the parts' name.
A Decurion was a Roman cavalry officer originally in command of 10 men.
Removed the dissolve FX when equipping your Atmosphere Arch-Gun.
Update 24.2 (2018-12-18) ‘ATMOSPHERE’ ARCH-GUN WEAPONS
It’s time we equipped some serious floor firepower! All Arch-Guns can be used on the ground - or as we like to call it ‘Atmosphere’ - with the use of a ‘Gravimag’. Gravimag is obtained from Clan Research, or as a one-time reward from the Orb Heist Phase 3 Bounty, and can be installed on any Arch-Gun (with an Orokin Catalyst installed) via the Upgrade Arsenal - similar to installing a Catalyst.
Comparable to the Archwing and K-Drive Launchers, a respective Gear item known as the Archweapon Deployer is required to activate your Atmosphere Arch-Gun. The Archweapon Deployer can be obtained by completing the Orb Heist Phase 3 Bounty.
Atmosphere Arch-Gun General Changes:
Atmosphere Arch-Guns consume Ammo as opposed to unlimited Ammo/Battery in Archwing. Specifically new Heavy Ammo Drops which can be found from Corpus enemies in Orb Heist missions. Heavy Ammo Drops also reset the 10 minute cool-down when picked up, or replenish Ammo if needed.
Atmosphere Arch-Gun can be summoned in normal missions with the Archweapon Deployer, but once Ammo has been depleted there is a 10 minute cool-down until you can summon again. The intent here is to allow you moments of beefy damage output, and not become just another Primary/Secondary weapon.
All stat changes are for Atmosphere Arch-Gun mode, Mastery Rank changes are global: