Mil-Spec
These upper receivers are high quality 7075 aluminum forged and hard coat military grade anodized, with milspec hardware. The top is Engraved 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 or FN or LMT lower. These are made for performance, and not for finish, but they look great. The Dog Bone uppers are made by a company called Demco Group in Florida, and Demco is a medium-sized military contractor and makes a number of high tolerance machined products for firearms and aerospace sectors. The upper receivers are milled by Demco from either Mueller or Anchor Harvey forgings. The end result will be the same, but collectors seem to seek out the Mueller forgings. You get your pick.
There are those who know and seek out the Dog Bone uppers and there are many who have never heard of them. Whichever you are, you will be very pleased to this upper part of your military style rifle build.
Charlie's also offers a similar upper receiver with no T-marks here