Still needs tweeking, but over all Im pretty happy with the out come. Theres realy nothing to keep the barrel stable. So it needs another internal block near the front of the reciever. Wouldnt be a problem with open sights. Everything would be attached to the barrel. So far it has a flat top piston & valve, open trans port. Still needs a lighter valve spring I didnt have one, but I wanted to get it together. As a result it doesnt dump all the air at 10 pumps. I cut the clip down to 3 shots so it didnt stick out so far. Also bent the retainer clips back & bored it out to 22 cal. Then bent the retainers back to hold the pellets. It has a 1322 barrel, & the bolt seats in the barrel not the plastic block. So far so good. Total so far $20 reman 760 + shipping. I made everything else. I should be looking at 620 fps with CPs, & 15 pumps.