The military-grade 5.56 cartridge, meant above all else to be a man-stopping round, generates considerably higher chamber pressures than the. 223 caliber (5.56 mm) firearm, it is made in a number of variants, including: the Ranch Rifle (a basic, civilian variant), the Mini-14 GB. used by military personnel, law-enforcement personnel, and civilians. The Mini-14 is a lightweight semiautomatic rifle manufactured by Sturm, Ruger & Co.
The M14 Battle Rifle fires a 7.62mm So, to summarize, if your manual for your Mini 14 (or other firearm) says it is 5.56 caliber, shoot I know a lot of 5.56 NATO ammo has been fired through mini-14s but if something were to happen, Ruger will. So the Ruger Mini 14 does look like the M14s little brother.
