Just purchased a 625 and when you pull the trigger slow or moderate everything is fine, timing, lock up, etc. However when you pull the trigger hard and fast the cylinder skips past the lock and can end up anywhere. The spring in the lockup tab seems fine, I switched the lockup block and spring with another one and same problem. The internals are spotless and well oiled. The cylinder grooves look good. The lockup tab does not seem to be binding on anything. The only thing I have not tried is to also put the trigger from my other gun in there to see if maybe the trigger is holding onto the lockup block a little to long but it does not look like it is, just not sure if the hand would still be in time well enough to actually try that. The only minor out of the ordinary thing I can see is that the lockup block does not rub perfectly in the center of the cylinder but is back just slightly. I am at a loss... any ideas?