This is every rifle the Marine Corps has issued to Marines in the service's 250-year history, from muskets to M4s.

The basic infantry weapon, the M16, is half a century old and the M4 is a shortened version of that. The rifle the M16 replaced (the M14) lasted less than a decade and the one before that (the M-1) ...

Army and Marine Corps Still Disagree over M16/M4 Bullet The U.S. Army’s M855A1 5.56mm round, inside and outside of its casing.

November 28, 2015: The U.S. Marine Corps has decided to equip all their combat troops with 17,000 M4 carbines and relegate their M16A4 rifles to support troops .Eventually all M16s will be retired and ...