jOe; In answer to your previous ??? about scarcity,units produced #s, production span, I'm afraid I don't have any definitive numbers for any of the above. I have the fortune/misfortune of owning 2 Bonehills in 10 gau. built on the system, not a bad system, I like it, but you will need a strong thumb, I wonder if only Bonehill used this method? You can go to IGC-historical questions- look at Bonehill Matthew Eclipse for some more info. also I believe the first issue of DGC has an article on this type of gun. --- John Can.