What makes a rifle a rifle?

I recently learned what the term “rifle” means. It turns out that it’s far more interesting than “gun with a long barrel,” which was my previous definition. Instead, it represents a mechanical innovation. The long barrel contains spiraling grooves on its inside, such that the raised parts of the grooves make contact with the bullet and impart spin to it.

“Like throwing a football?” I wondered, and sure enough, wikipedia uses that exact analogy! The spin gives the projectile additional stability and therefore range (and precision targeting).

The term “rifle” comes from the French rifler, a verb that means “to graze or scratch”. The rifles, then, are the spiral grooves or scratches — and the gun originally was called a “rifled gun.”

So a rifle does have a long barrel, to accommodate the spiral grooves and enough time to spin the bullet (>100,000 rpms!). But it’s what’s inside that counts.