Super light, but questionable quality and reliability - Fostech AR-15 Mg/Al Alloy Upper Receiver Stripped

This is not for a gun that you trust your life with. This is only for a an ultralight competition gun. This is a cast metal part. It is super light as advertised. The finish is some sort of painted on coating, it is not anodized (I am not sure magnesium can be anodized). The coating had several runs inside the upper which dried into thick drops that stood up so tall it inhibited the bolt carrier from being able to cycle. I had to sand the drops down in order to allow enough clearance to let the BCG cycle. And it still sounded rough, like there was a handful of sand in there even with lubrication. This is not for a gun that you trust your life with. This is only for a an ultralight competition gun.