Here's how it's done. I've done a lot of Ruger triggers, but have to say the folks above are giving you good advice. When your done you still have a trigger that isn't adjustable.
Ruger Model 77 Trigger
by
Michael Donaldson (aka Doc)
Webmasters note: This information is strictly for reference purposes only and is not intended for use by anyone other than a qualified gunsmith. The author, nor the webmaster will be liable for any incidents or accidents that occur through the use of this information. In laymans terms, if you are not a qualified gunsmith DO NOT MESS with your trigger. Leave it to the professionals!
The Ruger 77 trigger is one of the easiest factory triggers to rework. However, alterations to any firearm should be done only by a qualified gunsmith. This information is strictly for reference only and is not intended for use by anyone other than a qualified gunsmith. (guess why I had to put that in?)
Ruger firearms are designed to be strong, reliable, and SAFE. In doing this, they leave you with plenty of material to work with. In the model 77 bolt action rifle there are 2 main areas of complaint, that would be creep and weight. A third area could be considered as trigger over-travel.
Creep equals the distance the trigger must travel before releasing the sear. Weight equals the amount of force required to compress the trigger in order to fire. And over-travel is the distance the trigger travels after releasing the sear. If any of these are out of balance, they will be detrimental to the accuracy of ANY firearm. Ideally, the distance the trigger ‘creeps’ is imperceptible, the weight is light enough so as to not distort one’s hold on the firearm, and over-travel does not exist. With these definitions is becomes apparent that trigger WEIGHTS should vary according to the intended purpose of the firearm. A crisp, 3 pound trigger is as absurd on a bench rest rifle, as a 2oz trigger is on a hunting rifle. Remember safety is always #1. Keep the WEIGHT safe. All triggers should have minimal creep and no over-travel.
To fix the Ruger trigger one must understand its design. ‘Creep’ comes from the amount of trigger/sear engagement. Weight is a combination of trigger angle and spring tension, over-travel comes from the free swing of the trigger after the sear releases.
1. Standard factory trigger/sear engagement is about .035-.045. It equals the depth of the sear notch. This means that the trigger must move that entire distance before releasing the sear. Reducing this distance to .020 will safely reduce the perceptible ‘creep.’
2. The top angle of the trigger is steep enough that you must actually lift the sear in order to release it. Remember, the sear is already under tension from the bolt and firing pin. Increasing this angle to an even 90 degrees allows the trigger to follow a more natural arc and defeat the lifting action. Only enough metal needs to be removed to fully engage the sear, or about .025.
3. Next, a slight 45 degree bevel on the lead angle of the trigger will drastically increase the crispness of the trigger. Do only enough so as to extend perpendicularly forward about .005. This will actually help the sear to release, it is done on many custom 1911 triggers. With a .020 sear notch and the trigger done in this manner, you will still have a full .015 engagement of the trigger to the sear.
4. Polish all parts and bearing surfaces.
5. There are two solutions to the over-travel problem. (1) You can drill a hole in the front top end of the trigger for a small set screw and adjust accordingly. (2) You can drill a hole through the back of the trigger guard. The one in the trigger itself is theoretically better because it is supported against the action itself. Whereas the trigger guard screw is actually a third piece of connected metal. I have personally found no difference accept the trigger guard is easier to do and easier to set.
6. If the trigger and sear are wobbly because of the pins, simply purchase a couple of drill bits slightly larger that the existing holes, re-drill, cut off the bits and use them as pins. This is a key element when making the triggers extremely light.
7. I personally prefer the single stage triggers to the 2 stage trigger because my triggers are lighter than the 1st stage. You can actually pin the 2 sections if you like, just replace the connector spring with a pin. After you have done one, you will understand the principles, and should have no problem figuring the 2 stage. New springs are usually necessary in order to get very light triggers.
Some weights that I would recommend for intended uses would be 2-16oz (less than 1 pound) for a BENCH gun. Start heavier so that as you progress you can still feel the trigger. The ‘average’ hunter may not even realize they have touched a 2oz bench trigger. These rifles are ONLY chambered when aimed at the target, hence, they are not real conducive to hunting conditions. 16-40oz (1-2&1/2 pounds) on the average VARMINT gun. Most varmint hunting is done off of some form of rest where firearm is stabilized in a safe direction. Finally, the average hunting rig should be at least 2&1/2 pounds plus. These are just my suggestions and opinions.
GOOD LUCK and BE SAFE
