How does a compound crossbow work?

During the age of knights, the crossbow was among the jewels of modern engineering capable of piercing armor at long distances. During this time, the power of this weapon effectively repelled the enemy. Even though its shooting power and accuracy leave something to be desired except at short range, the modern version has become an effective hunting weapon. Indeed, today's crossbows have more advanced technologies such as anti-vibration, a silent shooting system, which constitutes a major argument for hunters and shooters.

Used for hunting, the crossbow is undoubtedly a very powerful weapon, precise and silent, provided that legislation allows it.

To benefit from optimized quality and performance, the crossbow can be equipped with pulleys. How do these compound crossbows work? We will discover this now in this article.

Crossbow with increased bolt speed

With a compound crossbow, using it is essential for the proper functioning of the weapon. With this type of weapon, the shooting power is centralized on the limbs. Unlike the limbs of a classic crossbow, those of a compound crossbow are generally stiffer. This rigidity will generate more energy. However, these limbs would normally be too difficult to cock by just pulling on the strings. This is why a pulley system is therefore necessary to reduce the force needed to stretch the bow string and cock the crossbow. As soon as the crossbow string is pulled, the presence of pulleys allows in turn to release the string while increasing the speed and power of the bolt. In the case of compound crossbows, gravity adds extra force for more power than a classic model with an arrow of the same weight

Shooting weapon that is simpler to use

By using a pulley system, cocking the most accurate crossbow is done more easily. In fact, with a classic model, you have to provide a colossal effort to pull the string, place the projectile on the rail. With the help of pulleys, the shooter will use minimal effort to carry out this entire cocking process. Moreover, the string tension with this technology is optimal for more efficient shooting power.

A weapon with a pulley system for more power

Generally, crossbow pistols are classified by their power, ranging from 80 to 260 pounds. This value corresponds to the tension measured on the string. For example, for deer hunting, opt for a crossbow with power ranging from 150 pounds to 220 pounds. Unfortunately, this activity is not authorized by current legislation in France. To practice hunting with a crossbow, you must travel to a country like the United States. With such power, the projectile will be able to completely penetrate the animal.

The toughest shooters will be able to manually cock 150-pound shooting crossbow to 200 pounds with a stirrup. However, the less robust must resort to compound crossbows to facilitate cocking the string up to a reduction in effort to draw the shooting string up to 30 %. Also, they can also use a string cocking device to reduce the draw weight by up to 50 %. Currently, most compound crossbow manufacturers can provide this device.

For high-power crossbows, assistance systems like the lever, and anti-return rack and pinion pulley are necessary. This way, it only takes 10 to 15 pounds of power to cock the string.

In terms of power, 1 pound equals 0.454 kg. For example, a 150-pound crossbow delivers a power of 150 x 0.454 kg, so 68.1 kg (or about a force of 668 Newton). To obtain the power in joules, simply multiply the force by the cocking length of the crossbow.