I just got a Mosin receiver mated to the UK-59 machinegun barrel....that was a trip. It involved my MIG welder welding the barrel in place, grinding it free cause headspace was too tight, and then rewelding the barrel back in place. Test fired it today with it tied to a tree and everything checks out good. First time I've headspaced anything. Anyhow....I want to put irons on it and am trying to figure out which williams/lyman receiver mounted peep sight to get and how to mount it so I can still remove the bolt. Do either of the companies make sights that rotate out of the way so the bolt can slide out? I also am wondering what model sight I could use that would fit the contour of the side of the receiver.