Decent tube to get your rifle running - Trinity Force Mil-Spec Buffer Tube Kit

This was the cheapest available option and it shows. The machining on the inside of the tube is very rough and it makes a ton of noise when you cycle the bolt. However, for a person that doesn't care, it is sturdy and mil-spec and fits fine. It looks exactly like any other mil-spec tube from the outside and functions fine. I put an Armaspec SMB buffer in mine and the operation is almost silent, although the poor inside machining is still apparent. Again, if you don't care about the sound of the spring/buffer sliding over a rough inner surface, this is the best possible buy for the money.