AR15A2 SP2 Carbine.

[imarangemaster]

That is my idea of the perfect light-weight, versatile carbine. Personally, a smooth side SP1 upper would be good also, but with MK262 MOD1 77 grn SMK OTM ammo, an adjustable sight is good, as it has 300-500 yard capability. When I was an FFL doing gunshows 89-92, I had one in my inventory that had a fixed stock. It was an A1 length A2 stock (Canadian C7 length). Very light and handy.