I have one, I made to changes to it, I installed a set of Tech sights "look like M1A sights" the Rear aperture is mounted to the rear scope mount holes. This works great make for a longer sight radius and swapping the barrel back and forth does not appear to effect zero I have never re zeroed the sights and I can easily hit a golf ball at 75 yards with the improved peep sight. Other modification I made was to drill out the bolt hold open so it acts like it should have come from the factory. I really like this rifle I use it mostly as a back pack rifle and just a plinker. Goes nice in the truck too as the case in not a conspicuous rifle case sitting on the back seat but just looks like a small backpack at first glance.