I purchased a flat, checkered MSH for my MKV. I think it came out of either a Colt, Springfield, Kimber, etc, anyway nice quality, not a knock off casting. After removing my Pachmayr MSH and transfering the internals over to the new MSH, and after installation back into the gun, two problems occur. The force to cock the hammer seems lighter and also there is no half cock notch. I reversed the procedure and reinstalled the Pachmayr MSH and everything works perfectly again. Depth of the spring tube in the new one is the same as the Pachmayr and all the internals used came right out of the Detonics Pachmayr MSH. Anyone got any ideas on the problem? Thanks