There should be a website dedicated to only these items. There are that many. Hollywood generates disasters every year.
6 Underground has a classic movie blunder that they should have caught, more really.
In military radio usage there are two words and in any radio conversation you choose one. “Over” is the first word, this means “I am done talking, your turn” The second word is “out” meaning “I am finished with this conversation.” the equivalent of goodbye. In any number of movies the line used is “over and out” which makes no sense in context of actual usage.
My other personal annoyance is gun handling. The good guys have come through 100 yards of mines and bad guys. All of a sudden, they are outside the door of the villain and all the good guys need to cycle the action on their guns which is not a quiet event. First, it is loud. Second, it means their guns were empty as they worked their way through the 100 yards of danger. Senseless.
How guns are used is equally annoying. To hit a target, one’s gun must be stable. Most people cannot “run and gun” with any degree of accuracy: maybe 1%.
A guy riding horseback, with a rifle and successfully shooting someone at 1,000 yards.
Automatic or semi-automatic pistols lock open when they are empty. In movies it does not work that way. (Thanks William Barlow for the edit suggestion.)
This man’s gun is empty. He does not have a loaded weapon.
Colt 1911 .45 pistols are single action. It must have the hammer back to fire. A 1911 with the hammer forward is useless in a firefight until that is resolved.
The revolver that fires 9 rounds. Most revolvers fire 6 shots and then they must reload.
Revolvers show the tips of the bullets. Any number of movies have shown no bullet tips meaning the gun is empty.
A special shout out about horses. In the real world, they mostly walk. Horses cannot gallop all day. Sigh.
I have a good friend who is ex army. For him, the uniforms and medals are usually wrong.
Last one. 1 million dollars weights 22 pounds. The ransom is 10 million dollars or 220 pounds of money, if all the money is $100 bills. The good guys bring a slim attaché case that is “10 million dollars” —nope, not how that works.
Best of luck.