I'm a little concerned about the .223's ability to stop an attacker. But if it's better than .45 ACP, then that's good enough
What makes you think .45 is so great? Afterall, it's a pistol caliber, and most pistol calibers suck.
NRA Certified Pistol Instructor & RSO, IDPA Sharpshooter, Project Appleseed Rifleman
Member NRA, GOA, SAF, VCDL