How accurate is an M4 rifle

Why an ex-military doctor would rather be shot with an AK-47 than an M4

They have become an integral part of action films like James Bond - weapons of all kinds. Exciting car chases or terrifying robberies only achieve the desired effect in films when weapons are involved. Because they can not only add injuries, but also make the difference between life and death.

The former military doctor Dan Pronk had to deal with weapons on a professional basis - and thus also with their devastating effects on other people. During his work, he quickly came to a conclusion: if he had to choose, he would rather be shot with an AK-47 than an M4.

Pronk writes in his article published on the military website “SOFREP” that he does not want to show what advantages one weapon has over the other and that he does not speak out for or against certain weapons. He just wants to explain scientifically what kind of gunshot wound certain weapons leave behind.

Shot of a rifle can be summarized in an equation

KE = 1/2 M (V1-V2)2

This is the kinetic-energy equation that Pronk uses to explain his train of thought. The mass (M) is halved in this equation, while the speed components (V1 and V2) are squared. This means that the speed is more important to the energy than the mass.

V1-V2 in this equation means that the projectile goes through a body instead of stopping. V1 here means the speed during entry into the body, while V2 means the speed during exit. So the speed changes as the cartridge penetrates the target.

If the ball gets stuck in the target, V2 drops out and is equal to zero, while V1 is the only speed variable.

Gunshot wound only as big as the cartridge itself

Pronk says that a good weapon has a decent weight and is very fast. The ball should ideally in the body get stuck and not go through it. So the entire energy of the ball is discharged in the body and thus also causes the most damage.

In addition to speed and mass, permanent cavitation is also of great importance, i.e. the hole that remains in the target. This permanent cavitation is always proportional to the diameter of the cartridge as it penetrates through tissue. For example, if a cartridge has a diameter of 2.5 cm, your wound is just as big. However, this can be life-threatening if vital organs or structures in the body are hit.

The M4 cartridge usually disintegrates into all its individual parts in the body

However, different rifles can hit different parts of the body at different speeds, according to Pronk. One gunshot wound will never be the same. However, the M4 leaves a relatively small entry wound, but a massive exit wound. It is common for M4-type weapons to leave massive bruises on the body - damaging loads of blood vessels as they travel through the body. The M4 also has another disadvantage: when the cartridge penetrates human tissue and hits bones, it breaks down into numerous individual parts that remain in the body. Because it is smaller and faster than the Ak-47's cartridges, it will deviate more quickly once it hits tissue. The acting shear forces shatter it into its individual parts.

Ak-47 cartridge, however, mostly remains intact

The Ak-47 cartridge, on the other hand, is a bit heavier and slower. When this penetrates the tissue, it tends to stay intact and not crack. As a result, however, it penetrates much deeper into the body. However, recovery from an AK-47 shot is faster than that of an M4. That is exactly why Pronk would always rather be shot by an AK-47 rifle than by an M4.

All in all, it always depends on the case, says Pronk. He had also seen serious injuries from Ak-47 rifles and also light M4 rifles during his work. How someone moves, what stature someone has, where exactly the cartridge will arrive and what damage it will do to the body, cannot be foreseen.