If you mean the jacket, it all depends on the caliber and maker.
There is no one answer- it depends on the rifle. They are generally less powerful than a full size battle rifle cartridge. The M16 rifle uses a 5.56mm bullet, the AK47 a 7.62mm bullet, etc.
The M16 assault rifle is chambered for the 5.56x45mm NATOintermediate rifle cartridge. It can also accept .223 Remington rounds.
Assault rifle.
The momenta of the rifle and the bullet are equal and opposite. The bullet has greater kinetic energy than the rifle.
Rifle and bullet (The bullet is dependent on the rifle to accomplish its purpose)
Depends on the gun, the bullet, amount of propellant, angle of firing, rifling, temperature, air pressure, humidity etc An average military assault rifle can fire a bullet almost three miles on optimal trajectory.
The SOAR (Special Operations Assault Rifle).
It appears you may be asking what is the round called fired from an assault rifle. It is a round. some are 5.56mm, some are 7.62mm. some are 8mm, some are 6.2mm (New Chinese round). Most are referred to by their chamber size. Rounds are comprised to two components, the ball or bullet, and the cartridge or brass. As a whole, rounds are often referred to as cartridges as well.
There are several different assault rifles - both by the true definition of an assault rifle and by the political motivated BATFE definition of a so-called "civilian assault rifle", manufactured by several different outfits. Which assault rifle did you have in mind, specifically?
The first true assault rifle debuted in 1942.
The barrel guides and accelerates the bullet out of the rifle, and imparts spin to the bullet to stabilize the bullet in flight.
You will need to define assault rifle, and where you live. A TRUE assault rifle is a machine gun, and transfers of them are tightly regulated by the Federal government. What most people CALL an assault rifle is nothing but a semi-automatic rifle, and in most of the US, does not require a license to possess.