Yes, but not for the reasons that would have it be mentioned here.
There exist several statements saying that the speed of their attacks, such as Johnny's nail bullets and Gyro's Steel Balls, vary depending on how "good" the Spin is, the better the spin, the faster the speed basically.
A good example off the top of my head would be when they're fighting Wekapipo and Johnny is like "****, I cant use the golden ratio here, if my spin was better I could attack faster tho", Wrecking Ball Arc.
Act 1 for example? Yeah that actually
is bullet speed (give or take depending on the situation), but something like Act 3? Is incomparably faster. The speed even shifts based on if they're doing it within the scale or simply getting better at using Spin.
"Coincidentally", bullets are never once shown as comparable to things beyond Act 1 or Desert Palm Gyro.
Which is to say, Part 7 mfs have a canon "Varies" speed, or at least Johnny and Gyro do.
Dudes like Diego treat bullets and guns as slow and doing feats Dale mentioned above (Diego straight up calls them slow at one point, and moves a fucktillion meters after one is fired at him once).
part 7 is messy though, not due to guns but due to characters scaling between each other, Wekapipo, Diego and D4C all ******* blitz each other at some point, obviously, that has issues. Weka being involved gets fucky too because he's hard-confirmed blitzed by Golden Ratio Gyro or Act 2, who is blitzed by Diego, which then leads back to point 1.