Naruto could solo via massive TBBs. Bullets from AK47 aren't penetrating his cloak. Saying all this, fodder ninjas with only shuriken and kunai would lose to a man with AK47 but main and even named minor characters from the Allied Shinobi Forces are far superior to regular humans with AKs.
Give the army airstrikes, machine guns and tanks then the fight could go either way.