We cut our optic mounts to secure the optic directly to the slide using full-length recoil lugs and the 2x 6-32 screws with maximum thread engagement directly into the slide. This ensures that the optic is deeply mounted and secured for hard-duty use. We do not pocket fit the optic front to rear as some milling companies do, requiring the specific optic for fitment. we have found that too tight of a pocket fitment leads to premature failure of the optic itself due to harmonic resonance from the slide. The tolerances of our recoil lug cuts are optimized to prevent sheer force loads from occurring on the screws. The precision of our optic cut is superior to any plate on the market and provides a Duty Grade interface for hard daily use.
With the Glock MOS system, the Mos plate does use 2 recoil lugs to secure the optic in combination with the 2 screws. One weakness in this system is the lack of required thread engagement from the Optic to the plate. Additionally, we have introduced another point of failure the 2 tiny screws that hold the plate to the slide.
The Machinist Handbook recommends that the length of steel thread engagement be 1-1.5 times the diameter of the screw. The Trijicon RMR (and any optic of the same footprint) is mounted to the MOS plate via 2X 6-32 screws. The .100" thickness of the MOS plate limits the number of threads from the screws that can be engaged into the plate. The 6-32 screws are .138" in diameter. Your thread engagement is less that the thickness of the screw at 74% of the width. At 32 threads per inch, there are only 3 threads engaged to the plate. This is if the stacked tolerances of the screw, plate, and optic are entirely perfect. If the screw is too long it will make contact with the slide below and lift the plate.
Let's look at the interface of the plate to the slide itself. This is retained by 2x M3x8 screws. Here we get good engagement with the slide. However, the M3 screws can prove to be an additional point of failure for the system. The screws can only be tightened to 13-inch pounds and even with our regiment of clean screws and holes, orange Permatex and sealing the top edge of the screw with an oil-based marker, if the plate is not limited in forward and rearward movement due to tolerances and fitment to the slide, failure will occur as the sheer forces are simply too much for 2 screws this small.