I was swapping barrels on a new to me Contender frame last evening; the mounted barrel was easy to remove and the replacement installed without issue. However, once closed with the replacement barrel, the action will not open. This is a G1 "easy open" 4xx,xxx frame. Both barrels are ten inch, heavy contour TC barrels. I thought removing the hinge pin would allow the frame to open. It did not. Any suggestions on how to get the action to open will be greatly appreciated!