1911 AUTO SLIDE MOUNT SCOPE BASE
1911 Old Bo-Mar
1911 New Bo-Mar
1911 Colt National Match Or Gold Cup
Most Bullseye shooters prefer the slide mount scope base compared to the frame or grip mount. The scope base is manufactured from 6061-T6 aluminum and Anodized Hardcoat. The Anodized Hardcoat has a hardness of 60-65 on the Rockwell "C" scale. By using the Anodized Hardcote plating on the scope base, will prevent the empty brass from damaging the scope base when it is ejected from the pistol. (see photo below) An angled ejection port is milled into the scope base to prevent the empty brass from striking and damaging the bottom of the scope.
The only difference in the old and new scope bases is the location of the front hole. The old Bo-Mar Rib had the first hole located 5/8 inch from the front of the slide and the new Bo-Mar Rib is 1 inch from the front of the slide.
The above photograph is of an experimental Scope Base that I made for a friend's 1911 Bullseye pistol that had a Bo-Mar rib with accuracy tuner installed. The scope base was made with a cutout to fit over the accuracy tuner. The scope base was not Anodized Hardcoat and the damage to the scope base from the ejected brass is shown in the photograph.