The U.S. Army officially approved the practice of painting the M4/M16 rifle, and issued a “how-to” manual. Some deployed troops and units have been painting their rifles anyway, and the Army move legitimizes the practice. However, soldiers still need permission from the unit commander before applying a camouflage paint scheme to their weapon.
An abbreviated “how-to” manual is here, while the full story can be read at the U.S. Army homepage.




