Bullets with a shifted center of gravity: reality and myths (3 photos)

Bullets with a shifted center of gravity are known to any person more or less knowledgeable about weapons. Various legends are associated with them, the essence of which boils down to the following: when it hits the body, a bullet with a displaced center of gravity begins to move along a chaotic trajectory; Having hit, for example, the leg, such a miracle bullet can come out of the head. All this is often told in all seriousness.

What are bullets with a shifted center of gravity?

The answer to the question about the existence of bullets with a shifted center of gravity is beyond doubt. Such bullets really exist, and have been for quite some time. Their history began in 1903-1905, when instead of the previous blunt-pointed rifle bullets, two types of pointed bullets were adopted: heavy ones for long-range fire and light ones for short-range fire.

These bullets had improved aerodynamics compared to blunt-point ones. They entered service with the armies of the leading powers of the world almost at the same time, and in Germany, the USA, Turkey and Russia light bullets were first adopted, and in England, France and Japan - heavy ones.

Types of bullets Types of bullets: A - blunt, B - heavy pointed, C - light pointed. Squares indicate the center of gravity, circles - the center of air resistance

Light bullets, in addition to improved aerodynamics, had a number of other advantages. The lower mass of the bullet, taking into account the colossal volumes of manufactured ammunition, provided significant savings in metal. The shooter's wearable ammunition was also increased. The light bullet had a higher initial speed (compared to the blunt-pointed one - by 100-200 m/s), which, together with its improved ballistics, increased the range of a direct shot. Experience in combat operations at the end of the 19th – beginning of the 20th centuries. showed that ranges of up to 300-400 m are the maximum for aimed shooting by an averagely trained fighter. The introduction of light bullets made it possible to increase the effectiveness of aimed fire at the specified ranges, with the same training of shooters. The advantages of heavy bullets at close ranges were excessive. They were needed only for long-range machine-gun and rifle fire.

Experience in the practical use of light pointed bullets has revealed one not very pleasant feature. They fired from rifles designed to fire blunt bullets. The barrels of such rifles had gentle rifling, which was enough to stabilize blunt-pointed bullets, but light bullets fired from them turned out to be unstable in flight due to insufficient rotation speed. As a result, the accuracy and penetration ability of light bullets decreased, and their drift under the influence of side winds increased. To stabilize the bullet in flight, its center of gravity began to be artificially moved back, closer to the bottom. To do this, the nose of the bullet was specially lightened by placing some lightweight material there: aluminum, fiber or pressed cotton. But the Japanese acted most rationally. They made bullets with a jacket that was thicker at the front. This solved two problems at once: the center of gravity of the bullet shifted back, since the specific gravity of the shell material was less than that of lead; at the same time, due to the thickening of the shell, the bullet’s penetration ability increased. These were the first bullets with a shifted center of gravity.

As you can see, the shift in the center of gravity of the bullet was not done for its chaotic movement when it hit the body, but, on the contrary, for better stabilization. According to eyewitnesses, such bullets, when they hit tissue, left fairly neat wounds.

The nature of wounds from bullets with a displaced center of gravity

So what caused the rumors about terrible wounds inflicted by bullets with a displaced center of gravity? And how true are they?

For the first time, incomprehensibly extensive (relatively small caliber bullet) wounds were noticed in relation to the .280 Ross 7 mm caliber cartridge. However, the reason for them, as it turned out, was the high initial speed of the bullet - about 980 m/s. When such a bullet hits the body at high speed, the tissues located near the wound channel find themselves in the water hammer zone. This led to the destruction of nearby internal organs and even bones.

Even more severe damage was caused by M-193 bullets, which were used to equip 5.56x45 cartridges for M-16 rifles. These bullets, with an initial speed of about 1000 m/s, also have the property of a hydrodynamic impact, but the severity of the wounds is not only explained by this. When such a bullet enters the body, it passes 10-12 cm in soft tissues, then unfolds, flattens and breaks in the area of the annular groove intended for seating the bullet in the cartridge case. The bullet itself continues to move with its bottom forward, while many small fragments of the bullet formed during breaking strike tissue at a depth of up to 7 cm from the wound channel. Thus, tissues are affected by the combined effects of fragments and hydraulic shock. As a result, holes in the internal organs from bullets of such a seemingly small caliber can reach 5-7 cm in diameter.

At first it was believed that the reason for this behavior of the M-193 bullets was instability in flight due to the too shallow rifling of the M-16 rifle barrel (pitch - 305 mm). However, when a heavy M855 bullet was developed for the 5.56x45 cartridge, designed for steeper rifling (178 mm), the situation did not change. The increased rotation speed made it possible to stabilize the bullet, but the nature of the wounds remained the same.

Based on the above, the conclusion suggests itself that the displacement of the center of gravity of the bullet in itself in this case does not in any way affect the nature of the wounds it inflicts. The severity of the damage is explained by the speed of the bullet and some other factors.

Wound channel from M-193 bullet

5.45x39 ammunition - the Soviet answer to NATO

It turns out that everything they say about the properties of bullets with a shifted center of gravity is fiction? Not really.

Following the adoption of the 5.56x45 cartridge by the armies of NATO countries, the Soviet Union developed its own intermediate cartridge of a reduced caliber - 5.45x39. His bullet had a deliberately rearward center of gravity due to a cavity in the nose. This ammunition, designated 7N6, underwent a “baptism of fire” in Afghanistan. And here it turned out that the nature of the wounds inflicted by it was seriously different from the same M-193 and M855.

When it hit tissue, the Soviet bullet did not turn over with its tail forward, like small-caliber American bullets - it began to tumble randomly, turning over repeatedly as it moved in the wound channel. Unlike American bullets, 7N6 did not collapse, since its durable steel shell withstood hydraulic loads when moving inside the body.

Experts believe that one of the reasons for the behavior of the 7N6 ammunition bullet in soft tissues is the shifted center of gravity. When it hits the body, the rotation of the bullet slows down sharply, and the stabilizing factor ceases to play its role. Further tumbling occurs, apparently, as a result of processes occurring inside the bullet itself. The part of the lead jacket located closer to the bow shifts forward due to sharp braking, which leads to an additional shift in the center of gravity, and accordingly, the point of application of forces already during the movement of the bullet in the tissues. In addition, the bullet nose itself bends.

Taking into account the heterogeneity of the tissue structure, we get a very complex nature of the wounds inflicted by such bullets. The most severe tissue damage from 7N6 ammunition bullets occurs at the final stage of movement at a depth of more than 30 cm.

Now about the cases of “got in the leg - went out in the head.” If you look at the diagram of the wound channel, you will indeed notice some of its curvature. Obviously, the entry and exit holes from the bullet in this case will not strictly correspond to each other. But the deviation of the trajectory of the 7N6 ammunition bullet from a straight line begins only at a depth of 7 cm when it hits the tissue. The trajectory curve is noticeable only with a long wound channel, while at the same time, with edge hits, the damage caused is minimal.

Theoretically, given the increased tendency of the 7N6 ammunition bullet to ricochet, a sharp change in its trajectory is also possible when it hits a bone tangentially. But, of course, if such a bullet hits the leg, it still won’t leave the head, for example. She simply does not have enough energy for this. When shooting at ballistic gelatin at point-blank range, the depth of penetration of the bullet does not exceed half a meter.

Ammunition 5.45x39

About ricochets

There is an opinion, typical of military personnel who have shot a lot in practice, about the increased tendency for bullets with a displaced center of gravity to ricochet. Examples are given of ricocheting from branches, from water and window glass when hit at sharp angles, or multiple reflections of a bullet when shooting in enclosed spaces with stone walls. However, the shifted center of gravity does not play any role in this.

First of all, there is a general pattern - heavy, blunt-pointed bullets are least susceptible to ricochet. It is clear that 5.45x39 ammunition bullets are not classified as such. At the same time, at acute meeting angles, the impulse transmitted to the obstacle can be very small, insufficient to destroy it. There are known cases of even lead shot ricocheting off water, which for obvious reasons cannot have any shifted center of gravity.

As for reflection from the walls of the room, it is true that bullets from the M193 cartridge are less susceptible to it than bullets from the 7N6 ammunition. But this should only be attributed to the lower mechanical strength of American bullets. When they encounter an obstacle, they simply become more deformed and lose energy.

Wound channel from a 5.45x39 ammunition bullet

conclusions

Based on the above, several conclusions can be drawn.

Firstly, bullets with a shifted center of gravity really exist, and they are not some secret or prohibited type of ammunition. These are standard Soviet 5.45x39 ammunition bullets. Stories about some specially placed “rolling balls” and the like are nothing more than fiction.

Secondly, shifting the center of gravity back was undertaken to increase flight stability, and not vice versa, as many people think. It would be correct to say that the shifted center of gravity is a common property of all small-caliber pointed high-velocity bullets, resulting from their design.

Thirdly, in relation to bullets of the 7N6 cartridge, a shift in the center of gravity really affects the behavior of the bullet in tissue. In this case, the bullet begins to tumble randomly, and its trajectory deviates from a straight line as it deepens into the tissue. This behavior of the bullet significantly increases the traumatic effect when hitting unarmored living targets.

However, there are no miracles like “hit in the shoulder, came out through the heel” and cannot be. This is a side effect of the use of small-caliber high-speed bullets with a durable shell, and not a specially designed characteristic. The role of a displaced center of gravity in the infliction of complex atypical wounds by such bullets and increased ricocheting is greatly overestimated by public opinion.