I have a smith and wesson 629 and I am thinking about putting a red dot on it but I want a small one not some a big bulky heavy thing and I dont want a big huge mount on the gun either, is there a red dot out there that can be mounted to the guns factory sight screw hole only without attaching a mount? I want to go this route for many reasons, one is the gun is heavy enough and I want to keep the weight down and I`d like to still be able to use the holster I have without making to much adjustments/alterations to it.