Ruger rifles often get knocked for their triggers. Let�s face it � replacement triggers from the likes of Timney and others provide a vast improvement. Ruger triggers have traditionally been on the heavy side with noticeable creep and over-travel and were something less than smooth. The older M77 triggers were adjustable for pull weight and over-travel, a feature that was dropped in the MKII triggers. The newer LC6 triggers found in the Hawkeye rifles also lack adjustment capability but, in my experience, are an improvement over the MKII triggers.
Redeeming qualities of the Ruger triggers include the simplicity of their design and the ease with which they can be greatly improved. Of the bolt guns in my safe, all but two are M77, MKII or Hawkeye Rugers. With the exception of the MKII VT .22-250, which has Ruger�s 2-stage Varmint/Target trigger, all have had the triggers worked on, some recently and some about a decade ago when I first got my Dremel. Last night I was digging through the safe and testing triggers as I went and came upon two Ruger rifles with triggers that, worked on long ago and acceptable, were not as good as those I�ve worked on more recently. Those two rifles go set in the front of the safe and their triggers will get reworked in the next few days. (One of the great things about cold and snowy weather is the time I spend at the reloading bench�)
The easiest and simplest improvement is to polish out the tool marks on the mating surfaces of the trigger and sear. This does not change any angles or reduce sear engagement (creep). I use Cratex rubberized wheels in my Dremel, starting with medium or fine abrasives depending on the depth of the tool marks. Once the tool marks are gone I use progressively finer grits, finishing up with the extra-fine. This leaves a mirror polish on the mating surfaces. Note that you don�t have to polish the entire top surface of the trigger, only the portion that actually engages the sear. That said, I do the entire surface because it looks nicer. I also polish up the top of the surface below the mating edge because the sear slides down this surface when the trigger breaks. Finally, I �break� the leading edge of the trigger�s mating surface, rounding it out very slightly using the extra-fine Cratex wheels and leaving a high polish on it. This helps smooth the pull, reduce drag (and thus pull weight) and helps the trigger break cleanly. Caution must be taken not to remove too much material as doing so reduces the engagement area. Just knock the sharp edge off the corner. If you round/bevel the corner more than .004� to .005� into the mating surface you�ve gone too far.
Polishing the sear�s mating surface requires an extra-fine wheel with a sharp edge that will fit down in to the notch on the sear. I don�t generally see a lot of tool marks in the notch but what are there on the mating surface get polished out, again leaving a mirror finish. The surface above the notch gets polished as well as this is the part that slides down the side of the trigger after it breaks. It probably doesn�t help in a measurable way but it looks nicer.
One other area I polish is the top of the sear where the bolt contacts it. This might help the bolt slide more easily against the sear but I doubt it has a measurable effect downrange. Once again this is probably just a cosmetic thing.
Reassemble the parts using a dab of Teflon grease on the mating surfaces and in the pin holes. Put the action back in the stock and see how the trigger feels. In my experience there is generally a considerable improvement in how smooth the trigger is with some reduction in pull weight.
Some triggers will still have excessive creep due to too much engagement depth. On M77 triggers the factory-set engagement depth may be as much as .045�, much more than needed. This is easily corrected by reducing it to around .020� to .025�. This may require removing a significant amount of metal by grinding or, preferably, using an abrasive stone on a piece of glass, laying the sear on the glass and working it against vertical edge of the stone. This will be slower than grinding but helps assure the angle on the edge of the sear�s notch doesn�t go off kilter. The best final depth, as measured from the flat below the notch to the outer edge, will depend on the leading edge of the trigger�s engagement surface and how much it was rounded or beveled when knocking down the sharp edge. The more it was knocked down the deeper the notch should be. The goal is to have about .020� of engagement, exclusive of the rounded/beveled area of the trigger�s leading edge. If the above has you scratching your head in puzzlement, get a Timney.
It is possible to reduce pull weight by changing the angle on the trigger�s leading edge of its mating surface. The factory angle is less than 90 degrees and actually causes the sear to lift a bit before the trigger breaks. Increasing this angle to 90 degrees will reduce sear lift and pull weight. Grinding without a jig is generally a bad idea, as with reducing the sear�s notch depth, so the stone and glass method is recommended to preserve other angles. After modifying the angle the edge should be broken as above. I think I�ve done this to one trigger but haven�t found it necessary on the others. Again, if you are puzzled, get a Timney.
Some people recommend cutting a coil off the trigger spring to reduce pull weight. I�ve never found this to be necessary and would recommend a full-length but lighter replacement spring instead.
One of the keys to success is not to hurry. Slow is your friend. Get in a hurry and you may find yourself in the market for a replacement trigger. Frankly, if you don�t have the patience or ability to do the work, a drop-in replacement from Timney or another manufacturer is a better choice to begin with.
I don�t have a trigger pull gage but I do have a Remington M700 with a very nice trigger and a Timney in my Interarms Mark X for reference. Even the best Ruger triggers I�ve worked on don�t equal the Timney. On the other hand, the Timney is on a rifle specifically built for long range work from at a bench and the trigger is a bit lighter than I prefer on my hunting rifles. With the exception of the two rifles mentioned earlier, which will have additional work done to their triggers in the next few days, my Ruger triggers are quite good for hunting purposes and a significant improvement over how they came from the factory. Due to the trigger design I would describe take-up as none, minimal creep, as light as I want them on a hunting rifle, very smooth and, for those without adjustment capability, some over-travel. The Ruger triggers also reset positively to their original position and sear engagement when pressure is let up before the sear breaks. This is a feature assisted by the factory angles on the trigger and is, IMHO, a very good thing on a hunting rifle.
All in all, I�m very happy with my Ruger triggers. Not needing replacement triggers has saved me enough to buy a couple more rifles, too.
