AR in .308 or 7.62

[Rob Roy]

Do regular lowers support .308 or 7.62? What is more fun to shoot .308 or 7.62? Is it easy to find 7.62 in local stores? I know that .308 is not a problem.

[Experimentalist]

My understanding is that "7.62" is in reference to 7.62 x 51 NATO, and "308" is in reference to the .308 Winchester cartridge.

The .308 is supposed to be the sporting version of the 7.62 (which typically is somewhat more potent than the .308). As far as I know all firearms chambered for .308 will also handle 7.62. It would be a huge potential liability for the manufacturer if their product couldn't handle 7.62.

[Rob Roy]

My understanding is that "7.62" is in reference to 7.62 x 51 NATO, and "308" is in reference to the .308 Winchester cartridge.

The .308 is supposed to be the sporting version of the 7.62 (which typically is somewhat more potent than the .308). As far as I know all firearms chambered for .308 will also handle 7.62. It would be a huge potential liability for the manufacturer if their product couldn't handle 7.62.

As far as I know, rifles chambered with .223 are not recommended to be used with 5.56, but only vice versa. I think the same applies to .308, doesn't it?

[Experimentalist]

Strictly speaking, you should always use the same ammo as is marked on your rifle.

And it is true that .223 Remington isn't loaded as powerfully as 5.56 x 45 NATO. Same holds true for .308 Winchester and 7.62 x 51 NATO.

However... these cartridges are virtually identical in external appearance. It is trivial to chamber one in a gun originally produced for the other. Any manufacturer with any sense will design their guns to handle the hotter loads without problem. Most often the user's manual will explicitly state as much.

[sorensen440]

.308 takes a different lower
if your talking about 7.62x39 then yes it will attach to a standard lower

[Experimentalist]

.308 takes a different lower
if your talking about 7.62x39 then yes it will attach to a standard lower

DOH, this makes more sense.

I was wondering why he was sweating the other cartridge pairing.

[Jarhead]

http://www.fulton-armory.com/308.htm

http://www.thefirearmblog.com/blog/2007/09/03/308-winchester-vs-762x51-nato/