MYSTERY MEN COMICS #13 (August 1940) gives us our first mention of vitamin 2-X, the formula which enhances the Beetle's strength. V2X was first mentioned in the radio series, and then carried over to the comics.
This story is a rather pedestrian entry with, other than the aforementioned V2X, follows the absolute most basic of Beetle formulas. Bad guys want to rob a pawn shop, and are willing to torture a girl for the safe combination. Car chase. Beetle gets caught in a seemingly life threatening spot. Mannigan gets coshed (but surprisingly Beetle is spared a bonking on the head this time!).
And , of course, at least one explosion.
Noteworthy is the use of a handgun on both the cover (by Edd Ashe), and in a single panel in the story. At this point , dealing out violence of the fatal kind to the bad guys is still a viable option for the Beetle. It's a pretty good assumption that he kills the thug on the rooftop of the pawnshop, as well as at least maiming another goon with the automatic pistol.
Gadgets this time around include the Beetle Sign, and his mini radio-phone.
Again, the art is signed by series creator Charles Nicholas, but is in fact by Larry Antonette.