I have not purchased any Lyman gas checks in the last few years because they are more expensive than Hornady. However the last Lyman's I bought were also of the crimp-on verity, and were indistinguishable from Hornady's, leading me to believe that they were made by the same manufacturer. Maybe someone has the inside info about this...Are both Hornady and Lyman gas checks produced by one (the same) manufacturer?