The brown No Shocs were standard equipment on M-79 Grenade Launchers when I worked for the Government. They were square cut on the bottom but would work on a small gun like an 0 frame Parker. Yup, I took a few of them home. I guess my DHE 20 has U.S. markings on the recoil pad. I've been waiting for that knock on the door for forty years now. I hope they don't notice that I also have a couple 1949 Mummy Bags still in high condition.