Originally Posted by allaroundhunter
And once more.....the idea that pistol rounds penetrate less than a defensive 5.56 round is false, and has been proven false many times.
Then that leaves the only reason to own a pistol caliber carbine as mag and caliber commonality. Perhaps noise although all will be very loud. Recoil from a 9mm rifle would be very light, but a .223 ar15 isn't bad either.
Ammo price is cheaper for 9mm, but .223 ammo is about the same price as .45acp and .40sw. That's all FMJ though, if i were shooting someone with FMJ, i'd want the most bullet energy possible and the .223 also has the advantge of tumble and yaw creating more damage with 3x the bullet energy over 45acp or .40sw.
Granted ammo price is negligible when buying in small quantities for home defense. Most would buy hollow point anyways. But some like to actually practice with their weapons too.