Science Fact or Cinematic Fiction

Eraser (1996)

Commando (1985)

John Wick: Chapter 2 (2017)

Do you ever think about the magic behind movies? We go into the theater and are awed by the harrowing stunts, crazy explosions, and death-defying action. Behind the scenes of every movie, there is a team making sure things run smoothly, look consistent, and look at least somewhat believable. One of the keys to a believable movie is to make sure the physics of the movie are correct. However, nothing is ever perfect and movies are no exception. Many action movies have unrealistic physics when it comes to firing guns because there is often little or no recoil, which violates the action/reaction principle of physics. In this paper, I will analyze three movies that have incorrect physics when it comes to recoil: Commando, Eraser, and John Wick: Chapter 2. I will also explain how recoil works. Lastly, I will go over why there is no recoil in some action movies. Although it is a small detail, more attention to recoil would make the action on the screen all the more believable.

In real life, guns have recoil. Recoil refers to the kickback when one fires a gun. The strength of the recoil depends on the size of the bullet and the powder charge that pushes the bullet out. Generally, the larger the bullet, the stronger the kickback. During recoil, the gun will go up and back, in accordance with Newton’s Third Law, with every action comes an equal and opposite reaction. The person firing the gun will feel the force in their wrist and/or shoulder, causing a strong jerking motion. In some cases, the recoil can be absorbed by the gun itself if the gun is heavy. However, there still will be some jerking motion. This motion is strong enough to dislocate the shooter’s shoulder in some cases, or cause bruising. Most people are surprised the first time they shoot a gun, because movies do not show the strength of the recoil.

In the 1996 movie, Eraser, with Arnold Schwarzenegger, there is a battle scene at the docks. One of the characters is wielding a weapon that shoots out a powerful beam that causes parts of the dock to dramatically explode. One would think that a weapon with such force would cause a recoil strong enough to knock the shooter backwards, but the character remains steady in his position and is able to fire multiple shots without once moving from his spot. This is clearly violating the action/reaction principle.

In the 1985 movie, Commando, also starring Arnold Schwarzenegger, there is a rampage scene in which Schwarzenegger battles soldiers. Armed only with a rifle, he is able to mow down several soldiers. Schwarzenegger may be a big guy, but it is hard to believe that his muscles would absorb the recoil of the rifle. Even if it did, the rifle itself would still move from the recoil, which it does not do. There is also a lack of recoil from the shotguns that the soldiers are firing at Schwarzenegger in the beginning of the scene. It does do well to note that at the end of the scene, there is some recoil when a soldier and after, Schwarzenegger, wield a specific a specific gun. It is interesting that there is inconsistency between the beginning and end of the scene. If this recoil consistency was applied throughout the movie, it would be a cheesy action thriller still, but at least the gun physics would be correct.

Unrealistic lack of gun recoil is not limited to old Schwarzenegger action movies. It can still be seen in modern day film, like John Wick: Chapter 2. The first instance of unrealistic physics in this trailer is the beginning where a character fires a huge missile launcher-type weapon at Keanu Reeve’s character, John Wick. The missile explodes in a fiery blast, breaking the window Keanu Reeves was looking through. Like the weapon in Eraser, there is barely any recoil, which does not make sense when every action must have an opposite and equal reaction. The shooter should have been knocked back by the force of the missile launcher. The next instance of unrealistic physics in this clip is the middle, where Keanu Reeves pulls out a shotgun at the party. He fires shots around the room, with no recoil or even a flinch. Even small shotguns have a recoil, and the fact that there is none violates the action/reaction principle. It goes to show that even modern day movies struggle with getting this detail down.

The final point I would like to cover is why most movies do not show gun recoil. The main reason behind this is that most guns in movies are prop guns or real guns that fire blanks. Prop guns, obviously are fake, and do not have the ability to shoot like a real gun. Firing a blank does not produce recoil because there is no mass pushed out from the barrel. As Newton explains, force equals mass times acceleration. Without a mass, there is no force. Without that force there is no action to produce an equal and opposite reaction. Real bullets are not used in movies for obvious safety reasons. In post-production, the editor will add the sound and flash of the gun. In some movies, the bullets and gun action will be animated. Some actors will simulate the recoil of a gun by moving the gun up after it fires. While this is a noble attempt, it fails to simulate the reaction of the effects on the body from recoil. However, not all movies fail to simulate realistic gun physics. There are some that pay attention to the small detail of gun recoil. In a movie, the action must serve the story, and sometimes details like recoil can fall through the cracks. Would Commando be half as entertaining if every time Schwarzenegger fired his rifle, he had to deal with recoil instead of continuing his rampage? Probably not.

To sum it all up, action movies often violate the action/reaction principle by not showing gun recoil. This is due to the nature of the business, in that the guns used in movies are fake or firing blanks. Though it is a small detail, obeying this principle would add to the authenticity of a movie, but sometimes it is more fun to have a nonstop thrilling action sequence with crazy explosions.