Why Luffy never tried the good'n'old Gomu Gomu no Pistol on Kaido?
This attack was the SHIT during east blue. It even KOed a sea king( Strong-as-fuck-END-GAME-BOSS who ruled the WHOLE SEA )
I really think he sould've used Gomu Gomu no pistol( vanilla ). It would've worked for sure. You think Kaido could tank a freaking pistol? I don't think so

Why Luffy never tried the good'n'old Gomu Gomu no Pistol on Kaido?
This attack was the SHIT during east blue. It even KOed a sea king( Strong-as-fuck-END-GAME-BOSS who ruled the WHOLE SEA )
I really think he sould've used Gomu Gomu no pistol( vanilla ). It would've worked for sure