re: Any have experience with Radical Firearms?

I bought that same upper, except in 556. Shot about 120 rounds through it and the gas block came lose. At the time I didn't have a clue about ar's so I sent it back to them to fix it. I shipped it out on a Monday at 12, and it was back in my hands wednesday at 2pm. They emailed me when they received it, and emailed me when it left them. If you have a problem with it, they have incredible customer service. I say give it a try. Its not like its going to lose any value in the next couple of months.