I could really use some advice on installing a pic rail mount on my mossy 500 20. I have a general idea of what to do and have the equip to do it, however, I really don't want to ruin my reciever. I guess my question is has anyone here ever drilled and tapped one of these receivers and installed a rail. Any tips as to depth, screw size, etc. would be so much appreciated. Also if you know of any where I can find a video of s