We've already seen it; you just have to look at that panel and I can at least tell that you're not that useless like
@nik87.
Luffy is holding a sword and he is still not a swordsman? Great, you're confirming my point once again. ;)
Besides, Luffy admitted that he is not skilled in swordsmanship and thus, you wouldn't see him holding a gun or a sword during a big war while clashing with the enemies.
It's actually hilarious how Oda has to draw every single kind of detail for you guys in order to judge whether he is proficient with a weapon or not.
Roger was holding a sword and a gun during the war and hence, Oda already established him as a dude who's proficient with various kinds of weapons.
@comrade, do you read this shit? Roflmao.