The Rifle, Assault Rifle, Heavy Rifle, and Shotgun are all double rendering while in 3rd person. First person works just fine. Also, the Bazooka, Minigun, and Pistol are fine. I don't know how to fix.

Can confirm. Also happens for other players in multiplayer.

Do you have the CavesandCliffs backport mod installed? This mod is causing the problem in my modpack, when i remove it the bug is gone. Unfortunately i cannot find a way to fix it without removing the mod. Try it, if you have it installed.

Just an incompatibility with another mod. This issue should no longer exist in 1.18 and above.