I just installed them on the two Ruger Mark III I have and they work great! The trigger is smooth and brakes around 3.5 lbs. And, the magizine flyes out like it was greased. It was very easy to install, it comes with very good directions and just took about twenty minutes for both guns. Just remember to keep the old parts just in case you sell the gun and the buyer wants it stock or have to send it back for service.