That's a factory Sabre Defence rifle. It's by far the most accurate AR-15 I've ever owned. MidwayUSA sells the fluted barrel assembly for $450. It sounds a little pricey but when you consider the parts that come with it like the YHM gas block/flip up front sight and all the fluting work the price isn't really that bad.
Sabre Defence is 1st class stuff in my book.
Terry
