Question: what is the difference between an m4 and ar15?
Answer: The M4 is used by the US Military, while the AR-15 is not. The M4 is capable of fully automatic, and had a select fire selector, while the AR-15 is only semi-automatic. The M4 is a military weapon, and while the AR-15 was made for the military, is has never seen service, making it not a military weapon.