Thought they had to be AMERICAN calibers. What the hell is a 5.56 or a 7.62? Are they some kind of commie or illegal immigrant size?
-Old Time Hunter
Now i truly hope you are joking. Sir if you are not joking, your not dumb or stupid, just uneducated. I an not suggesting uneducation in general , specifically pretaining to firearms.
7.62x51mm NATO - This was a standard NATO ammunition. Not sure when it was adopted, but nonethe less all (or most correct me if I'm wrong) NATO countries use 7.62. The M14 rifle, that is still used in Iraq by our soldiers today, is chambered in 7.62x51mm NATO. It is also used in M60 when that was used before it was virutally replaced by the M249 SAW. 7.62x51mm NATO is NOT to be confused with 7.62x39mm (7.62 short, 7.62 ComBlock). 7.62x39mm is used in the AK-47 (other AK models like the AKM) and the SKS. The .308 Winchester is a "civilian" 7.62 NATO that operates at higher pressures and slightly smaller so not suggested in 7.62 NATO chambers.
5.56x45mm NATO - Current standard of NATO and our military. 5.56x45mm NATO is the chambering for most M16 derivadives, including, but not limited to the M16a2, M16a3, M4a3, xm177. This was adopted in the early 60's along with the introduction of the M16, then later offically adopted by NATO. Just like the 7.62 NATO it has a civilian counterpart, the .223 Remington. The .223 can be fired in a 5.56 NATO chamber, but not visa versa.
I hope this was informative and articulated. If this did not inform you, having prior knoledge, my hopes were to inform others.
Happy trigger time!