Murray Goertzen, age 14, of Carson City, Nev., for his question:

HOW DOES THE M .1 RIFLE WORK?

The M 1 rifle, which is a U.S. .38 caliber eight shot semiautomatic weapon, was the basic rifle of the United States Army and Marine Corps. The United States Army used the gun, which is also called the Garand rifle, from 1936 to 1960.

The M 1 rifle is gas operated. The bullet uncovers a small hole before it leaves the barrel. Compressed gases behind the bullet rush through a port to a piston, driving it back against the operating rod. The rod rotates the bolt to unlock it, pushes it back to open the rifle and helps eject the cartridge case.

A recoil spring closes the bolt and rams a fresh cartridge into position to fire when the trigger is again pulled. The M 1 fires one shot at each trigger pull.

A government designer named John Garand developed the M 1 rifle in 1929. The M 1 replaced the M 1903 bolt action rifle.

The United States Army now uses the M 14 and M 16 rifles.

The M 14 and M 16 work in a manner similar to the M 1. But the M 14 and M 16 have cartridge boxes that hold 20 shots. Both rifles are also automatic and can fire between 120 and 200 rounds a minute with special attachments.