Just wondering if anyone out there would have any advice for me before I take it to a gunsmith. I bought an older cooey single shot 410 (worked when I bought it). I had the barrel and receiver re-blued. When I got it back and put it together ... the hammer won't lock in the "cocked" position. If I take the barrel off, I can pull the hammer back, and it locks in place like it should. I am stumped ... because these are very simple guns. Any help would be appreciated.