No I wasnt kidding. Was I just mistaken? I thought 7.62x54mm was the round that is also considered .308?
Firearms chambered for 7.62 are most likely NATO.
The 7.62x51 NATO chambered rifle will fire and function .308 Winchester. The .308 Winchester is a tad bit smaller and I think there is a head space difference?
The same goes for the 5.56. It will shoot .223 Winchester but again the .223 is a tad bit smaller.
There are many 7.62 ammunition types in 51mm / 39 / 54 etc and some pistol rounds as well.
Any experts out there that have a chart?