30 cal upper

[7.62 Nato]

Has anyone ever attempted a .30 cal. carbine upper ? I think it would have a lot of practical uses.

[uzimon]

weak cal.
why not 7.62x39?

[7.62 Nato]

Instead of pistol cal carbines. A lot of agencies won't use the rifle calibers and are not happy with the pistol caliber stopping power and reliability. I was thinking the AR in .30 carbine would be a more acceptable compromise.