I was setting up my Ruger RPR and I’m using a Vortex CM-534 cantilever mount, I cannot get the mount to tighten completely on the rail. The screws tighten until the wings bottom out and the mount can still move. I tried it on another section of pic rail that I have and it works like every other mount, only rail I’m having an issue with is on this Ruger. Are they using a different pitch or is this possible just bad machining out of the box from the factory?