I have come into possession of this barrel. At first, I thought it was a Glock barrel, and it has the same dimensions as a Glock 19 barrel, and the lower tang on the barrel has the "step" profile that looks like a Glock, but the rest of it, including the "9MM" stamp on top and the semi-circle tab on top of the barrel look like a S&W M&P. I own neither a Glock nor a S&W MP, so the only frame of reference I have had was a trip to the LGS across the way, and the thinking was that it was either a Glock 19 or some flavor of S&W MP. Any input would be greatly appreciated. Here are the dimensions: OAL from the tip of the barrel to the outer semi-circle tab = 3.955 Barrel Diameter = .59 (entire length of the barrel) Chamber width (outside squared off area) = .5955 Semi-circle tab width = .398 Kind of puzzled as it has characteristics from both S&W and Glock (I know they are very similar anyway). If it is a Glock 19 barrel, I might do an 80% lower. Not sure what to do with it if it is an MP barrel. Thanks in advance!