Why are cartridges usually made of copper rather than steel, aluminum, lead?

Bullets are usually coated with copper or lead plated, but copper bullets are more common.

The reason is short: Manufacturers have found a way to expand, rotate and do other nasty things once they hit the target. Lead is rarely used because it is hard enough to deal massive damage but is easily deformed when exposed to high temperatures, so the bullet expands when fired, up to 3 times larger, resulting in easy obstruction and deflection. towards the target.

Bullets are usually made of brass.

What is the shell made of is related to how the metal reacts under pressure, resists natural corrosion, the ability to return to its original hardness ...

A suitable ammunition casing must be strong enough to withstand the pressure of firing and have sufficient elasticity to return to its original form after being slightly deformed by the pressure of firing.

Shell cartridges must also be easily molded into the correct shapes during production so that the bullets fit into the cartridge when loaded.

Among metals, brass is not so hard that it can create sparks when touching hard surfaces, a major factor to consider when loading and pressing a bullet into a gun.

Copper is also naturally resistant to corrosion, can be stored for a long time (up to several decades).

It is this combination of properties that makes brass a very popular shell material.

However, copper also has a disadvantage that it is more expensive than other metals that can be made into cartridges.

The US wants to develop bullets that when dropped to the ground, they will grow into trees
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