Gentlemen, I hate to show my ignorance, but.....I recently ended up with 2 Contenders, both older models. One opens smooth and easy, the other takes a good squeeze to open it up. Both barrels are the single lug style, the grips are not interfering. Seems I've read on some threads about an easy open frame......I didn't know what was being referred to. Any body help me out, about when T/C may have went to this other style of action. ( the newer serial numbered frame is the easier of the two to open) Thanks in advance.....Mike