Compact Assault Rifle - Suppressed - 5.56x45mm NATO - USA - 700 RPM - The M4A1 is the most recent variant of the CAR15 family.  The barrel length was specially selected to provide compactness without sacrificing reliability.  The barrel is also contoured to provide for the attachment of a M203 grenade launcher.  It also has improved handguards to prevent the uncomfortable heating properties of earlier CAR15s during rapid fire. D.E. Watters