Bullet was incredibly powerful and it’s safe to say that he was stronger than Luffy at the time of the movie. That said, the gap continued to shrink and shrink until in Wano I would say Luffy is stronger. Bullet would not be able to overpower him anymore unless you think Bullet’s on Kaido’s level and I don’t think so. Luffy just wins in all the relevant stats so this will be a clean outcome. Luffy wins.
It’s time for Bullet to make his debut onto the blog. This guy is extremely powerful to say the least as he was able to take on the complete Worst Generation. Usopp may have solid sniper skills but he just would not be able to contend with this level of power. Bullet’s haki would protect him from any and all attacks. At that point Usopp is out of luck. Bullet wins.