I have the Timney in mine. I have heard some people knock them but it gives my M77 a pull of 1 1/2 lbs with with no creep and no excess overtravel. I had a gunsmith order and install mine, but the installation was not difficult. He took out the old trigger. Then he showed me where the fitting would have to be done. There is a raised spot on each side that you file to fit your gun so it does not bind but is not to loose. Then you file the safety part of the new trigger. It is made longer than it needs to be and should be fitted to your gun so that there is just enough clearance for the safety to move through its full range but if its filed to short the gun will fire while the safety is on. That is why they say to have a gunsmith install it. But it is not hard if you go slow and put the trigger in and check it often. While doing the safety portion of my gun the smith had to stop and wait on several coustomers and when he finished I had finished the fitting and was putting the trigger in for the final time. He inspected it then ask if I would like to come help him with some things in his shop.