Painter; Olympic made a .30 carbine AR15 but eventually dropped it because of low sales. its such a natural caliber for an AR because the same 5.56 bolt would be used. Then you need a .308 barrel with a 5.56 barrel extension and a chamber insert for .30 Carbine. The hardest part but not out of the question for a good tinkerer is building an M1Carbine magazine into an AR mag body. Once you got it basically running, you probably would have to lighten the action spring and buffer.
Yes, the traffic is awful in 'Nawthun Vuhjinyuh' so I try not to go up there unless it can't be avoided. I might ride up, catch the Metro at Springfield and ride over to see a Redskins game every so often when I feel the need to 'wear the hair shirt'.Then there's a huge gun show in Chantilly a few times a year that's worth going to - its even more fun to go to it because it's in the shadow of 'The Beast' (DC), one of the most gun-hatin' holes in the world.