Mr. Pettit has confused the tool with the results of its (mis)use. A firearm is an inanimate machine incapable of destruction and infliction of pain without being wielded by a human. The fact that modern semiautomatic and fully automatic firearms make it easier for humans to kill and maim greater numbers is than the firearms based on earlier technology, in this case, irrelevant.
Mr. Pettit is being petty.