Yep I was right. Part 59 in the diagram. 1.5x2.5 NBR 90. You can see the damage in the pics. Makes ya wonder how it was holding air perfectly before I degassed to decrease my first reg. The tip of the valve rod oscillates through this o ring when hit by the hammer. Should make the valve housing cap a little deeper without the hole. See third pic, circled in red. They have room to do so. Anyway, I happy again. Thanks for all the suggestions. The airgun community and AGN is awesome! Thanks again guys.
