After Major Kong lists the contents of the emergency ration kits, he says "Shoot, a fella could have a pretty good time in Vegas with all that stuff." His lips are saying Dallas instead of Vegas. President John F. Kennedy was assassinated in Dallas shortly after filming was completed, and the producers did not want to remind anyone of sad events during a joke.
When Mandrake finds the radio, it is on the shelf of an IBM 1403 high-speed printer, with the cover open. The printer is running; anyone who has ever been around a working 1403 printer knows that they are very loud. Operators had to shout to be heard. The printer is not making the loud noise it should be making while running in the shown 600 lines per minute mode with the cover open.
De Sadesky says that the fallout from the doomsday device has a half-life of 93 years, but then he also says that the fallout would circle Earth for 93 years. This is a contradiction: half-life is the time it takes for radiation to be halved, not completely dissipated. It is common however for people to confuse these concepts, and the dissipation time for the fallout from a nuclear weapon salted with cobalt is indeed about a century.
Towards the end of the film, when Strangelove is fighting with his renegade right hand over control of his wheelchair and punches it several times out of frustration, the Russian Ambassador (Peter Bull) clearly corpses (laughs) at Peter Sellers' performance and then quickly regains his composure.
De Sadesky claims that the doomsday device are large nuclear weapons that have been jacketed with a compound of Cobalt and Thorium. While Cobalt is indeed a first choice when making such a weapon, using Thorium makes no sense at all since it will not be activated by the blast to form any dangerous fallout.
While checking the contents of his bailout kit, Slim Pickens removes his Colt 1911 pistol, cycles the slide and then pulls the trigger and drops the hammer. To do this without checking to see if the pistol is unloaded is an unforgivable breach of basic rules of safe firearms handling and would never be done by anyone with military training.
When General Turgidson asks about Strangelove's name he gets told that the Doctor Americanized his name from "Merkwuekdigliebe." This is a mispronunciation of "Merkwuerdigliebe",
which in turn is a slight misspelling of the German term "Merkwuerdige Liebe", meaning "strange love".
General Turgidson tries to dismiss de Sadesky's claim of the doomsday device by saying radiation from a nuclear fallout is "down to a safe level after two weeks". But the idea of creating so called "salted" nuclear weapons by using cobalt in them was put forth by Leó Szilárd - the "father of the atomic bomb" - already in February 1950, and it is this concept that doomsday device in the movie is built on. The general would be well aware of salted bombs and their capabilities in 1963 when the movie takes place.
When Gen. Ripper and Capt. Mandrake are using the belt-fed machine gun, in one shot Mandrake is holding a chair over his head for protection, but when it cuts and the camera is behind them and Ripper crawls away from the window, Mandrake isn't holding the chair, and the closest chair is 10 feet away from him.
When the missile is tracked approaching the bomber, we see the radar screen with 6 concentric circles. As the first report comes in, the missile is just outside the 6th circle, and is reported at 60 miles away. The next report has it at the 5th circle and 50 miles away, so each circle must be an increment of 10 miles. However, when the missile is at the 2nd circle, it is stated to be only 10 miles away. Before it reaches the 1st circle and starts deflecting, it is said to be 7 miles away instead of greater than 10 miles.
Although General Turgidson says (in the War Room) that "the aircraft will begin penetrating Russian radar coverage in about 20 minutes," the map of Russia on the Big Board shows several aircraft either very close to, or in some cases actually over, the Russian border, well within the range of Soviet military radar.
General Turgidson learns from his secretary, Miss Scott, of General Ripper's ordered attack on the USSR at 3 a.m. Washington D.C. time. However, the concurrent scenes at Burpleson Air Force base (somewhere in the Western United States) take place in the daytime.
When General Jack D. Ripper is firing the .30 caliber machine gun with the assistance of Group Captain Lionel Mandrake, he is holding the machine gun by the barrel. In reality, this would quickly cause serious burns and would not be possible for more than a few seconds.
The Coca-Cola machine squirts drink into the face of Colonel Guano after he shoots holes in it. However, there would be no reason for the bottles or cans in the machine to be under pressure, as the shooting wouldn't have shaken them up. Also, the bottles wouldn't be stored to the side of the vending door (where the bullet holes are), but above it.
The style of machine shown mixes tap water from a water line attached to the building's plumbing with carbon dioxide and drink syrup stored in tanks inside the machine under pressure and dispenses it into a paper cup that drops into a chamber in the door which is plainly visible in the shot. Therefore, it is quite plausible that water would squirt from the machine under pressure if the tanks or water lines were pierced by gunfire. This style of machine used to be quite common when this film was made in the 1960's, but are now fairly rare, as the machines had to be restocked with raw drink syrup (a different tank of syrup for each drink flavor) and recharged with carbon dioxide. Otherwise, if the syrup, carbon dioxide, or both ran out, you often received either a cup of plain soda water, a "flat" soda with no bubbles, or worst of all, a cup of plain water if both the syrup and carbon dioxide tanks were empty.
In reality incoming missile threats are not detected by a radar on an aircraft as depicted in the movie, but by a Radar Warning Receiver. An RWR assesses threats by detecting a ground radar as it directs its tell-tale emissions at the aircraft to guide a missile to it, or by detecting a radar on-board the missile itself.
The depicted capabilities of the airborne radar in the B-52 are fantasy. The B-52 never had a fully rotating radar with a PPI scope, it had a ground attack radar, and the gun turret radar didn't operate like that. No airborne radar in the 1960's could detect a target as small as a surface-to-air missile at 50 miles away. A sweeping radar would not be able to display the missile exploding in mid-sweep.
When Major Kong is reading the contents of the crew's survival kits, he mentions, "one automatic pistol". The weapon shown as he reads that description aloud is a typical semi-automatic pistol, not a fully automatic weapon which continues to fire as long as the trigger is depressed - in other words, a machine gun. However, the correct military designation of the standard issue sidearm depicted is "Automatic Pistol, Caliber .45, M1911-A1."
When the radio operator gets the go code (FGD135) he opens the code book and pages to the "L" page, then the "J" page, then finally to the "F" page. All 3 of those pages are exactly identical, with all of the "F" go codes in fainter type. The "F" page go codes are in much darker type.
The panel in the B-52 labeled "Auto Destruct" is in fact a flare launch control panel. Visible under the black paint are the instructions
1) PULL COVER DOWN
2) MOVE MASTER (CENTER) SWITCH DOWN
3) RELEASE A FLARE BY MOVING EITHER SIDE SWITCH"
Several times during the film, when the B52 is shown in flight from the side, even though the camera angle "pans" with the aircraft when banking (turning), there is no change in the angle or geography of the scenery on the background plate footage - it still looks as if the plane were in straight level flight.
The plane's navigation acetate we see repeatedly towards the end of the film is an rough outline projection of the whole globe. This would be completely useless for its supposed purpose of targeting a single missile base.
The first time we see the War Room, there's a binder in front of General Turgidson where the spine reads "World Targets in Megadeath". Its position changes during the long scene, and at one point we can view the contents, and the binder is empty.
The goof items below may give away important plot points.
Incorrectly regarded as goofs
Since there has never been any real 100 MT nuclear devices detonated, stock footage of other, much smaller, devices stand in as "actors" for the 20-30 and 100 MT detonations in the film. Clearly we can forgive Stanley Kubrick for not using real 100 MT nuclear weapons to make a movie. Also, megaton explosions would not be photogenic for the rapid cuts of the end sequence since they expand much slower on film, as they are being filmed from much further away. Finally we can assume that in the early 1960s there wasn't much declassified material of megaton explosions available to the public as such explosions were achieved only less than ten years earlier.
When Mandrake made the phone call to the president, the communication system was supposed to be dead. However, there are no doubt multiple phone lines going into a major air base, and it is quite conceivable that a public pay phone would be on a completely separate phone system than the direct line to SAC Headquarters. In fact, Mandrake did mention the possibility that it would not be working.
After having shot the Coca-Cola machine, Colonel Bat Guano leans down to grab the coins and is subsequently hit in the face with a stream of the soft drink. Keenan Wynn's head was too high when the stream began to spew toward him, and he can be seen lowering his face down into it to produce the full comedic effect.