I'll try to find it, but someone posted recently that they are all they shoot. I shoot the Hornady version (I suspect they are the same bullet from the same supplier, but I have no proof). The Hornady's give me way under sub MOA with my Stag AR.
Edit: It was a post on the other forum I frequent. They are just a hair cheaper than the Hornady, and like I said, I suspect they are the same bullet. Below is my range report from the Hornady. I see no reaso why you couldn't get similar results with the Midsouth brand.
AR 15 with Hornady 55 grn SP Range Report