Figured out what was making this one so stiff on opening and closing. The lock bar was pressing very hard on the blade. When I open it the lock bar snaps extremely hard into place. Took it apart and compared it to my 21s and noticed the lock bar was much further in than they were. I pushed the lock bar outwards a few times to take some of the inward tension off. It is smooth as the 21 now and locks up perfect.