[Steelharp]

Ok, help an ignernt ol' fool... what is the difference?

Mikey D...

[Art Eatman]

In the cartridge, no difference in the external dimensions of the case.

In the loading, no difference in the chamber pressure that's ever shown any obvious signs. I shot up a thousand rounds, +/-, of "surplus" GI ammo from Fort Hood--in a Mini-14--back in the 1970s, and "never noticed nuttin".

From what's been said at TFL, apparently the chambers in military-issue rifles are maybe a thousandth or so "looser" than spec, for ease of cycling. (I do not know this as absolute fact.) And, the leade is a bit longer than in sporting-rifle chambers.

How the amount of leade (freebore in front of the chamber) affects chamber pressure is a function of the length of the bullet, the depth of seating, and the shape of the ogive. So, if the Mini has less leade than a military M16, it's not enough difference to matter with 1970s-variety military ammo.

Art

[Jim K]

5.56mm is the military designation; .223 Remington is the civilian designation. Other than that, military rounds must be loaded with full metal jacket bullets and are also loaded with special bullets like tracer and armor piercing. Civilian ammo is often loaded with FMJ bullets for target shooting, but is also loaded with soft point or expanding bullets for hunting.

Jim

[Kahr carrier]

Yep.