All Roc moves are Gear 2 and Gear 3.
Red Roc is Red Hawk but larger (i.e. Flame application due to speed of the move). He blows up his fist like Gear 3, but it moves at the speed of Gear 2.
Compare to Red Hawk against Hody, it's the same, just bigger than Red Hawk.
Roc Gun was used last chapter. It's just Gear 2/Gear 3, but a normal punch (not fire):
While you don't see steam, you can see that
A) His arm is not fully drawn in the punch, characteristic of Gear 2
B) His arm is inflated, Characteristic of Gear 3
Finally, this chapter proves those points, with not only Roc Gatling belpw, but both the unnamed punch and kick he does this chapter (not the one to the face). Keep an eye out for steam/Luffy's arm not being drawn (due to speed) and his hand/legs being inflated:
Compare this to his typical Gear 3 elephant gun/gatling, it's much bigger and slower (no steam, shows the stem of Luffy's arms):
Hopefully really drives the point home that Roc moves are a Gear 2/Gear 3 mix, not exclusively AdvCoA/CoC by default. It just happens that he decided to use these with that Haki.