M-16's are .556 rounds. I do not know where anyone got .223. 240-G Machine gun is .762 and the Squad Automatic Weapon or SAW is also a .556
Just a point of fact. Carry on.
Its 5.56 Nato which is the same as .223 inch just like 7.62(7.62X 51) Nato is the same as .308 (7.62X51) different for 7.62X "39" different case size for the AK/ sks crowd.
Pays to KNOW what is up/down when the $hit goes round. Don'tcha know.
That would be 5.56 and 7.62, as in mm compared to .223 which is inches.
Uh, better watch where you put those decimal points! .223 is the 'English' caliber designation. 5.56 is the metric caliber designation & is in millimeters. They are the same caliber bullet, but can be attached to varying cartridges.
7.62 is also a metric caliber designation in millimeters. There is some minor diameter differences in say, 7.62x39 vs 7.62x51.(I'm not talking about the casing diffs either) The x39 round really is usually a .310-.311 diameter bullet (like the old Lee Enfield but lighter weight, usually 124gr, vs 174-220gr for the Enfield). The x51 is a .308 diameter, but they get the same metric designation, presumably because they are so close in size it wasn't deemed practical to carry it out to the thousandths.