Well this doesn't bode well for Black Ops 6's iteration of Gunsmith. Helpful CoD YouTuber TheXclusiveAce recently published a breakdown of Blops 6's barrel attachments and determined, amazingly, that most of them are essentially useless.
That leaves the Short Barrel that increases mobility (handy for fast-paced playstyles) and the CHF Barrel that increases headshot damage—even this one is only situationally effective depending on the gun, since extra headshot damage doesn't always mean it'll take fewer shots to kill. The lesson here, which has actually been true for the last handful of CoDs, is that you're better off focusing on attachments that improve the gun's handling, like grips and underbarrels, and ignoring ballistics (unless you're going for longshot kills with an SMG).
Why does Black Ops 6 have prominent attachments that barely do anything? It could be a simple oversight, but the more likely reality is that Treyarch didn't design these barrel attachments for Blops 6—they're for Warzone, where huge maps and long gunfights mean you absolutely want the most potent mix of velocity/range on all of your guns.
That's all fine and good, except that they still serve little purpose in 6v6 Blops multiplayer—a game that millions of people are playing—and the game makes no indication of that. It's up to you to stare at the stats and figure out that the green arrows going up aren't actually helping you, which is pretty counterintuitive for a system that's supposed to make your guns better or more interesting. If this were any other series and we weren't so used to the needs of Warzone clashing with the rest of Call of Duty, this sort of bad game design would be laughed out of the room. But unfortunately, it's business as usual for the best-selling franchise.
You'll get your chance to use Blops 6 barrels for their intended purpose this week. Black Ops 6 Season 1 begins on November 14, integrating Warzone into the Blops 6 fold alongside Omnimovement and a new Resurgence map, Area 99.
