I was never the one that was into the tactical doodad thing when I got into shooting AR15 rifles.   My idea of a rifle is a 30/30 or a M1 or FAL rifle.   I understood the ballistics of the .223 round and knew what is was good for and always thought that I should stick with the 20 inch heavy barrel for the best terminal ballistics.   Well, then I actually started learning about close combat and understood that toting the longest barrel gun and the heaviest barrel is going to mean slower speed and too much weight.

The M4 is hands down the best close quarters combat Carbine.   I have trouble referring to the M4 as a rifle, but I think that it really isn’t.   The beauty of the AR15 family or rifles is the easy swap in swap out changes you can do with an AR15 Upper.   AR15 Uppers are made by dozens and dozens of manufacturers and the quality and design differences are very diverse.   LWRC is making what I believe is the best M4 style carbine for US Citizens, but CMMG, Bushmaster, DPMS are making less expensive yet combat worthy AR15 Uppers.   Understand what the M4 is designed for and using the proper ammunition will put you in a much better position that using a handgun for those environments.