Re: What's in difference in
the difference is the .223 rem in a SAAMI minimum spec chamber, the wylde chamber is one that can utilize ammo that is either .223 remington or 5.56 Nato. The Nato and the Remington are close but slightly different. The .223 AI is an improved version of the .223 giving the shoulder a sharper angle and an advantage in case capacity and velocity.
Dave