Audio problem: When Enders kills White Horse, he first tries to shoot him with his .45 and you can hear the hammer falling on an empty chamber. But if you look at Enders' pistol the slide is locked to the rear and there is no way the hammer could have fallen on the empty chamber. This also occurs earlier in the scene when Ox is trying to shoot the Japanese.
Revealing mistake: In the Saipan village, during the surprise Japanese attack, the Christian Slater character is wrestling on the ground with a Japanese soldier. When another Japanese soldier charges in with his bayonet, Christian Slater turns his wrestling foe up on top of him to take the bayonet. As soon as the bayonet strikes, you can see the bloody special effects 'wound' charge go off in the wrong spot - about 3 inches HIGHER than the bayonet strike. When the shot changes, the SFX mistake wound is no longer there.
Factual error: When the Christian Slater character is introducing himself to the Nick Cage character while running on the beach, he mentions that his nickname is "Ox" because he comes from Oxnard, CA. He then explains that Oxnard is "just north of Hollywood a ways". But look at a map - Oxnard is practically due WEST of Hollywood, not North. Someone from Oxnard would know that.
Factual error: When Ox and Whitehorse are being over run at one point Ox points his .45 at the Japanese and repeatedly pulls the trigger (you can here the click , click ,click sound of the hammer hitting an empty chamber.) This is a mistake because in order to do this the .45 would have to be a double action pistol its not you must manually cock it to get it to fire the first round (after that it cocks itself hence the name Auto Loader).
Factual error: Throughout the film, Joe Enders is wearing an M1 Helmet. But his helmet looks like a non-WW2 type and possibly Vietnam era. From the side of the helmet, it is a higher cut along the sides. This is a usual indicator to the era of the helmet, as WW2 M1 helmets are lower along the ears for better protection.