A couple pages later, he drops a number of aircraft bombs by hand onto a munitions factory, which is "destroyed amidst terrific carnage!" (Just to be sure, I checked my Websters: "Carnage: the slaughter of a great number of people, as in battle; butchery; massacre.")
There is a site or an article out there somewhere listing every use of a gun by Batman. Maybe we should compile the early Superman murders leading up to the first mention of his oath?