How did m14 rifle work?

Answer 1

When the cartridge is fired, the bullet is driven through the barrel, At one point a small hole is drilled in one side of the barrel. As the bullet passes that hole, some of the gas that is pushing the bullet through the barrel enters that hole, and pushes against the gas piston. The gas piston drives the bolt to the rear, extracts the fired cartridge case, and ejects it from the rifle. A return spring pushes the bolt forward, where it strips a fresh cartridge from the magazine, and chambers it- ready to fire again.