Factual error: In the Brighton street scenes the parading air cadets are wearing service issue pullovers. These were not introduced as part of the uniform until the mid seventies. During the sixties air cadets would have been wearing battledress tunics.
Factual error: Unfortunately, the most striking scene in this - or any other - film is complete nonsense. During the helicopter attack they play "Ride of the Valkyries" on an ordinary tape deck through two smallish stereo speakers in order to scare the enemy prior to the attack. Okay, let's be clear - helicopters are LOUD. Very, very loud. The enemy would hear a flight of six helicopters approaching from thirty kilometers away. You simply could not play music loud enough to overcome the engine noise of 6 choppers, not without an enormous speaker rig and the power to run it. They are using bog standard home stereo speakers, not the huge bullhorn speakers used later in the war to intimidate the enemy. The music would be barely loud enough to be heard inside the helicopter, let alone outside it. This does not refer to the music playing on the film's soundtrack; Kilgore makes it clear he is playing music from the helicopter and he intends it to be heard by people on the ground.
Factual error: Although it's already been mentioned that the scene of the shuttle being stolen from the back of the 747 is impossible because the shuttle wouldn't be fueled while being transported, it should also be noted that even if the shuttle was fueled, it would still be just as impossible: During the getaway, the thieves ignited the shuttle's 3 main engines to get free of the 747 and escape: the thing is, the shuttle's main engines are fueled entirely by the large external tank the shuttle and the solid fuel boosters are attached to during liftoff, and once the tank is jettisoned, these engines cannot be used. The only engines the shuttle's internal fuel feeds are the reaction control thrusters, and the Orbital Maneuvering System (which are the two smaller engines located in the bulges just above the main engines). Both the RCS thrusters and OMS engines are almost totally useless within the atmosphere, so even if the thieves managed to get the shuttle free of the 747, they could only get it as far as it would glide unpowered: In fact, they could probably get it further if it wasn't fueled. It should be noted that this is not a fictional, futuristic spacecraft: It's a bog standard shuttle, stolen from NASA, on the back of the modified 747 used by them to transport the orbiter from its landing site to Cape Canaveral.
Factual error: Throughout the film the British infantry are armed with carbines. These were intended for issue to cavalry and are much shorter than the infantry issue Martini-Henry rifle.
Factual error: All Borstal inmates were subject to the same mandatory haircut of short back and sides, yet many types of hairstyles are shown in the film.
Factual error: When Santini is reporting into Beaufort, he refers to the Marine behind the desk as "sergeant." However, the rank on the Marine's sleeve indicates he is a Master Gunnery Sergeant. Unlike in the Army, referring to any rank other than E-5 as "sergeant" is considered an insult in the Marine Corps, and no Marine would ever refer to a Master Gunnery Sergeant as "sergeant." The proper form of address would be "Master Guns," "Master Gunny" or "Top."
Factual error: When Brian fires a rifle at the shark from the boat, he fires the rifle multiple times very quickly. The rifle he is using is a bolt action rifle, which must have a bolt part moved before each fire. He does not touch the bolt.
Factual error: According to the novel on which the movie was based, the "40" in the title refers to the number of players on a football team. But by the time the movie was made, football teams had 45 players. The coach even says Nick Nolte was just one of 45 players. So the title of the movie really makes no sense.
Factual error: The action in this movie takes place in 1869, yet half of the handguns are 1873 Colt Peacemakers, and the remainder that are Army or Navy Colts are all cartridge conversions, which were not available until 1871.
Factual error: During the period in which Apollo is trying to bait Rocky into a rematch, Rocky puts the TV on and sees a sports report in which Brent Musburger announces that the Los Angeles Rams defeated the Tampa Bay Buccaneers on a late field goal by Frank Corral. The movie takes late 1976-ish. The Rams did not play the Buccaneers in 1976, and Frank Corral did not join the Rams until 1978. The game in question occurred during the 1978 season.