I suggested this before in these forums, and unfortunately, there isn't an animation for the Colt, Tec-9 and Uzi (I used the IFP mixer and opened anims.ifp and GTA3.img and in colt45.ifp, there is no firing animation).
I also found a file called tec.ifp which had the firing anims from GTA VC but replacing tec.ifp for colt45.ifp on weapon.dat didn't work (I think the game crashed, idk, I don't remember, it was way back then in 2018).