In my opinion, the gold barrel is one of the least useful gold items right now. It's essentially just a purple barrel mod with extra shiny and a different model, as it only reduces recoil as much as the purple one and the muzzle flash doesn't even matter now since they removed it from the shooter's POV.
in order for the gold barrel to actually be a high tier item, I would suggest that the devs consider making it act as a suppressor as well, unlike the standard barrels. this would make it actually as valuable as other gold items and potentially deadly, especially with weapons such as the longbow, hemlock and other high tier weapons. audio is an extremely important aspect of this game, and having an attachment that silenced gunshots would make the gold barrel legitimately valuable and allow for some crazy endgame and third party plays.
in addition to this, I would suggest that the select fire hop up be changed to gold and added as a compatible hop-up for additional weapons such as the hemlock and p2020 (for full auto). additionally, allowing the p2020 to accept both the gold barrel and the selectfire receiver would change it from a bottom tier weapon to potentially the best weapon in late game, especially if both hammerpoint rounds and the selectfire receiver were used together on the same p2020, but this would be a balance consideration.
as of right now, the only gold hop up in the game is the anvil receiver, which is kind of lame in my opinion. to offset the lack of gold hop ups (no turbocharger), I would suggest making the select fire receiver a gold attachment and also make it compatible with more weapons that have limited or no fire selectors.