When I get my mount in, I'm going to put a 2.5 x 7 pistol scope on mine for hog hunting, as I detest open sights. The one I ordered attaches to the front rail and then uses a replacement screw for one of the frame pins - maybe two of them - to get extra support. The plastic frame of the Glock will not support a scope mounted with the rail alone, like the one I have on my metal framed 1911. Both types are high enough over the slide to have no operational problems - mount does not touch the slide - and the open sights can be used by looking beneath the scope mount. Same mount works for red dot "scopes", so they don't need to be mounted on the slide. Racking the slide on the 1911 is more difficult than without the mount, but can be done. To lock the action open, I use an empty magazine, and the mount can be easily and quickly removed from the rail, then replaced without losing zero. For the Glock - which has no exposed hammer - I have a "charging handle" that fits to the rear slide serrations, making it easy to rack the slide with the mount and optic in place.
