What is a rifle bullet made out of?

Several possibilities. Usually it is made of brass. However, there are cheap steel case rounds, and expensive nickel case rounds. Most often, though, they are made of brass. Once fired and ejected...

Bullets (the projectile that is fired from a gun) are typically made of lead. Lead is soft, dense, and inexpensive. In many cases, the lead core will have a jacket made of harder copper/nickel alloy,...

Most bullets are made from lead. Some will have copper jackets around them, but the bullet itself will be lead.

That's like asking "When was your car made?". Without more information the question is not answerable.

Almost every country makes rifles