[Philysteak527] modified a Nerf rifle, making it semi-automatic thanks to the powers ... and manufacture a bolt-action that fits in the gun, works with the Nerf ammo, and uses a CO2 canister ...

This is for the Celestial Nighthawk Golden Gun ... nerf that will arrive in Destiny 2 shortly after. In the Destiny 2 update 8.1.5 patch notes, Bungie delivered a buff for the Sentinel Shield.