I've had 3 so far... still have 2. All have been right at 50% and have stayed there. None have ever shown any signs of slipping or the lockbar bending even under unusually strong spine pressure. Honestly, 50% is about as early as I like on a frame lock. Any earlier than that and I pass the knife on to someone who likes that kind of thing. I am not a fan of early lockups. To my simple mind, more contact equals a more secure lockup.