Other mistake: Chucky cuts Andy's Achilles tendon from under his bed. Throughout the rest of the movie, Andy should have a limp from such a severe injury. However, he has no trouble walking or running in subsequent scenes, nor does he show any signs of injury.
Plot hole: No amusement park ride company would ever produce a prop scythe that was as sharp as depicted in the movie.
Other mistake: During the breakfast scene, Sgt. Botnick tells Andy he needs a trim on Wednesday, but he had just given him a haircut the previous day.
Character mistake: When Chucky is looking up the information about Andy on the computer, the word juvenile is misspelled "juvinile."
Plot hole: At some point during the war games exercise, headquarters would have eventually discovered Sgt. Botnick's body, and then they would have immediately stopped the exercise.
Plot hole: There is no way a military academy wouldn't teach their students the first rule of using a firearm: when you are given a firearm, you must always check if it is loaded and what kind of bullets it has. So there is no way Chucky could have switched the paintball shells with real bullets without someone noticing.
Other mistake: When Charles is thrown away and gets dumped in the back of the garbage truck, he screams for the garbage man who hears him and jumps in. There's no way he could have heard Charles screaming or the cadets hear the garbage man screaming from the marching field. Front loaders are loud and nearly impossible to hear screaming even near the truck.
Answer: Military schools usually have gun ranges, so they would have live ammunition for that.
pross79