Do these grips move around at all prior to installing the screws? The pins should be able to keep them positioned with no slop.
I had trouble with the Rohrbaugh aluminum grips because of this. I suspect the pins 'share the load' with the screws during recoil, and if the pin holes are too big then the screws take all the side load. A partial box of WWB caused the loctite'd screws to loosen and the pin holes to become ovaled.
I ask because I'm thinking about the checkered grips, which I suspect would magnify the problem I had with the aluminum ones unless the pin holes are correct.