WTH??
If a bayonet is useful, you've already lost the battle! Can you reference how long it's been since a U.S. soldier killed an enemy with a bayonet fixed upon his rifle or carbine?
Does our military still issue bayonets? Try fitting an M16 bayonet on an M4. They both incorporate the same front sight with integral bayonet lug. The problem is that the sight on a M4 is several inches further behind its flash hider than an AR-15 or M16. An appropriate bayonet for the M4 has never been designed, manufactured or issued.
You would be better off with a good K-Bar. Lash it to a spear if you run out of ammo.
RE Bayonet:
It’s the symbolism... :^)