I was never a big fan of the .223 or 556 caliber until I actually got off the bench and started doing real gun fighting.   I started out like many, with a Russian AK variant which was extremely reliable, but when it came to target engagements out to 400 meters and for close quarters gun fighting, there was a substantial difference in hit ratio.  Hit ratio was something that I never dealt with before because it was all about penetration and accuracy.   Now I know that being able to shoot a reliable rifle doesn’t mean you are going to win a fight, it’s all about hits and who gets the hits first.

There have been times when an AK74 type of rifle has done almost as well or equal to an M4 Carbine, but the shooter has to have more experience in gun  handling skills to keep up.  I compared the close quarters hit ration of the 6.8 SPC and found it to be closer to a 7.62×39 AK than a .223 variant. CMMG upper receivers are something to be considered if you are looking to mess around with bullet calibers.  Muzzle hop or flip will affect  your accuracy and speed and that is something to be concerned about.  Room to room and house to house fighting is something which occurs in seconds and putting 5 hits on paper is better more reliable at stopping a threat than one bad hit.   Bullet penetration is also something that can be over blown when it comes to CQC because that is a bad thing in a hostage situation.