So like, I do enjoy theorycrafting for the sake of fic writing etc., but questions like this really have no answer in canon because early volumes went by rule of cool and a LOT of this stuff didn’t get solidified so you end up with contradictory lore along the line. Also I refer to the wiki a lot but I’ve come across a decent number of instances where they’re clearly headcanoning in explanations because there never were any (a good example being Sage’s listed allusion).
One big reason Dust kinda falls apart when you start trying to think about it too hard is that they can just create matter (the best example of this is when we see earth dust being used), though you could turn that around into a positive by saying e.g. when Yang shoots out bursts of fire that’s not just like gunpowder but an actual explosive decompression of phlogiston that she can ride as it displaces the matter around it.
All that said, personally I’ve always seen Ruby’s gun-fu movement as dictated by the sheer size of Crescent Rose’s sniper rifle. I’ve even seen fanfics that lean into it by saying she uses anti-tank ammunition.