Does wearing a bulletproof helmet help much when getting hit by a bullet?

Bulletproof helmets are highly safe and reliable helmets. It is specially designed to meet the stringent requirements of military, security and public order enforcement forces. Gamers are probably no stranger to the "82 armor" bulletproof combo including a vest and hat (Kevlar + Helmet) for $ 1000 in Counter Strike.

The "82 armor" bulletproof combo in Counter Strike.

To test the protection of bulletproof helmets, the YouTube channel "Крупнокалиберный переполох" performed an interesting test. They used a variety of guns with different calibers to shoot at the bulletproof helmet. This hat is worn over a ballistic gel human head model, inside is a plaster skull.

Despite the fact that a modern military helmet can protect the head well from bullets, when the helmet collides with steel, the kinetic energy of the bullet does not disappear but will be dispersed and scattered. partially absorbed by the hat, and part of it will affect the head of the person wearing the hat.

If we are lucky, we will have large bruises on our heads due to hematoma. Admittedly, it's better to feel pain than to die instantly, but in some cases the consequences can be much more sad.

Experimenting with silent pistols

In this test, the gunner stood 5 m from the target and used a silent pistol of 9x18 mm caliber with a silencer attached.

This type of bullet has a small muzzle velocity (about 300 m/s) and a small kinetic energy, only 250J – that is about 1/8 of a normal 7.62×39 mm AK47 bullet.

The bullet penetrated the helmet shell but was retained by the lining so it did not affect the prosthetic head. Moreover, this silent gun is designed to shoot at very close range, so a distance of 5 m is also not suitable.

This bulletproof helmet can indeed withstand 9x18 mm . bullets

On the second attempt, the gunner fired from a distance of only 50 cm, but the bullet still did not penetrate the helmet lining. Thus, this bulletproof helmet can indeed withstand 9x18 mm bullets of silent pistols.

Followed by AK guns and sniper rifles

The gunner uses an improved AK submachine gun with 7.62×39mm ammunition. The ammunition was developed in 1943, but went through many changes, and was considered officially completed in 1949. However, due to many fluctuations in the change of fire pulse, it was not until 1961 that the ammunition became real. completion.

In terms of power, the 7.62x39 mm bullet is much superior to the 9x18 mm bullet. 

Today the 7.62x39mm ammo is the standard ammunition in many armed forces. Strong bullets, good bullets, durable, stable. The technology of making bullets is somewhat more complicated than that of producing other types of ammunition, but after automation, bullets are produced very quickly and cheaply, and are easy to produce in large quantities.

In terms of power, 7.62x39 mm bullets are much superior to 9x18 mm silent pistol bullets. The velocity of the warhead is 715 m/s, and the initial kinetic energy of the warhead is 2019 J.

Would a sniper shot do anything to this bulletproof helmet?

So can a single shot from an AK submachine gun or a sniper rifle do anything to this bulletproof helmet? And will the person wearing the hat be injured so badly that the skull fracture or, luckily, the cervical vertebrae?

Tested with AK guns and sniper rifles with 7.62x39 mm . ammunition