Mil-Spec
Charlie's and our friends at Potomac Armory have selected a US manufacturer with exceedingly high standards, ISO 9001 standards, etc. This OEM manufacturer makes receivers for many other brands from top forgings.
Quality here is tops. Comparable to Colt, LMT, and Daniel Defense. These upper receivers are high quality 7075 aluminum forged and hard coat military grade anodized, with Mil-Spec hardware. The top is painted with T-marks. These are military grade uppers, which means there could be handling marks, and the finish might seem chalky. This will go well with a Colt, FN, or LMT lower. These are made for performance, and not for finish, but they look great. Occasionally, we are removing them from a completed upper receiver, so some grease might be evident.
Charlie's also offers a similar upper receiver with no T-marks here.