Here is the buba peep sight I made. I drilled an over-sized aperture and sighted it in using a pin through some adhesive aluminum auto tape. I back-filled with JB Weld. When pressed firmly onto the aperture, the tape dimples a bit making almost a lens shape. I pressed tape on both sides while it set up and allowed JB to ooze out of the pin-hole, then cleaned it up as it set. The adhesive on the tape acts as a release agent. Before removing the tape, I drilled using a very small bit between my thumb and forefinger, using the pin hole as my marker. The whole thing is very small—it's a very small receiver—and is help on once again with JB. I degrease the top of the receiver with denatured alcohol and the bottom of the peep was roughened. The receiver also has a key where the scope mount would lock up which I'm thinking will help hold it on there. If it comes off I'll drill and tap it but wanted to avoid doing that. It appears very sturdy and I can lift the rifle just by the peep... I don't think it will come off easy. I'm actually a little concerned that I might not get it off easily if ever I do want to take it off. I have left the rear sight on there for now, and the peep and the rear confirm each other perfectly for a 6 o'clock hold at 100 yards.