The nuclear bombs in Dr Strangelove looked nothing like the actual devices B-52s carried at the time. Kubrick modeled them to look like intercontinental ballistic missiles of that era, not the Mk41 (B41) thermonuclear bomb Major T.J. Kong would have been carrying in real life. The Mk41 entered service in 1961 and was the only bomb in the US arsenal capable of yields in the 20–30 megaton range, as specified in the movie. Kubrick’s bombs even have roll marks painted on them (the black and white checkerboard patterns) which were used on rockets to help observers detect roll around the vertical axis during testing. They weren’t used on gravity bombs (ones that were simply dropped from planes), and they certainly wouldn’t have been painted on a bomb already in active service. And of course, a real bomb wouldn’t have the Air Force insignia painted on it, either. B41’s (the real thing) were rounder and shorter than Kubrick’s models, and would have been painted drab green. Kubrick almost certainly knew this — after all, he was able to accurately re-create the interior of a B-52 at a time when that information was still classified. He likely chose the ICBM look because it was longer, more dramatic looking, and more pleasing to the eye when viewed in black and white. The explosion you see when Kong hits the ground was a 31-kiloton test that was part of Operation Buster-Jangle (the Easy shot). Visually it gets the job done, but Kong’s 20-megaton bomb would have produced a much bigger explosion.
Before being cast as Dr. Strangelove’s gung-ho bomber pilot Major. T. J. Kong, (after Peter Sellers injured his leg, plus Sellers was having trouble with a Texas accent!), actor Slim Pickens had starred almost exclusively in Westerns, with nary a comedy part to his name (much less a political satire). This didn’t pose much of a problem, however, as Kubrick deemed the actor’s natural cadence and decorum to be perfect for the cowboy soldier.
Kubrick led Pickens to believe that the film was supposed to be a serious war drama, prompting him to carry himself as he might in any of his Western pictures. Furthermore, according to James Earl Jones (who made his film debut in Dr. Strangelove) and Kubrick biographer John Baxter, Pickens behaved, and dressed, identically onscreen and off … not because he was “staying in character,” but because he apparently always acted like that!