[P8riot]

NATO 7.62 x 51mm round is same as .308 Winchester.

Not so.

[mainevet]

Close enough.

[broken_arrow1]

NATO 7.62 x 51mm round is same as .308 Winchester. -- "Not so"

There are headspace differences between the two rounds. The .308 go-gauge is 1.6300, the .308 no go-gauge is 1.6340. The 7.62 go-gauge is 1.6350, the 7.62 no go-gauge is 1.6405. Since NATO military ammunition can come from any NATO country, and the goal is the ability to interchange ammunition, the military chamber is larger.

Provided we use common sense, headspace differences shouldn’t cause us to quake in fear. If a person is using new, Mil-Surp ammunition; and not reloading it, then the headspace becomes a non-issue. The round is fired and expended.

http://www.surplusrifle.com/shooting2006/308vs762nato/index.asp

Close enough.