If your 8# trigger return spring is lighter than stock. Test extensively in fast DA fire. Those are stout little guns, but they make poor clubs when dodging incoming fire.

 

The stock trigger spring weight is 10lbs. Once everything is in place, I'll take it to the range and check things out. If there's any question about reliability, the stock springs will go back in. Slick is one thing, failing to be reliable is a non-starter. The 8lb trigger return spring is the only option Wolff offers. I looked at the spring kit from Mcarbo, and theirs is even lighter, the trigger return spring being 7.5lbs and the hammer spring being 9.5lbs. I'm sure that's smooth, but I felt those weights were a bit light for a carry gun, so I went with the Wolff springs. I'll have to look into the shims also.

 

Hammer shims, trigger shims, & hammer dog shims from Ruger Double Action Shim Kits to Reduce Trigger Pull

They'll make a huge improvement

 

Wolff is a reputable outfit. Likely it'll be good. Piece of mind is worth checking for though.

 

This is a good kit that comes with shims for the hammer and trigger.

Ruger SP101 / GP100 Trigger Spring Kit

Upgrade your Ruger SP101 or GP100 with the most complete American-made Trigger Spring Kit. Reduce heavy trigger pull, improve accuracy, and enjoy a smoother, more responsive shooting experience.

www.mcarbo.com

 

As you note best to test out the result after the changes. I have a SP101 with a 8 lb trigger return and 9 lb Wolff mainspring and it works. However, it has minimal endshake, headspace near minimum and have given the hammer step a treatment mentioned by Iowegan to ensure maximum firing pin protrusion. In order to get the 8 pound trigger return spring to work usually requires cleaning out the channel in the trigger guard for it with a drill bit and/or polishing with some fine grit sandpaper or ?? wrapped around a dowel.

 

I did both the shim and spring kits. I believe it is best do do both since one helps the other. Believe it or not, I think the shims did just as much if not more to improving the feel of the gun. I did mine many years ago and followed a printed version of a tune. I wish I could find it again so I could share the link but you should be able to find a good one.

One of the things I remember surprising me was the amount of "debris" I got out of the trigger return spring channel and for that matter.....overall. It was worth doing the work just to get everything cleaned up.

 

I went to the Mcarbo site and watched the video for installation of their spring and shim kit which included all the polishing they suggest. Since I had nothing better to do at the moment, I decided to play along. I did everything short of installing the new springs and shims since they aren't here yet. Just the polishing and cleaning out the trigger return spring channel made a great difference. The new Wolff springs should be here Tuesday, and those won't take any time to install. I may go ahead and order some shims, if I'm going to do it, I may as well do it all.

 

I have used Wolff Springs with good results, and I have experimented with different hammer spring strengths. If I find one is too light, I replace it with the next heavier spring. I know this requires a lot of shooting to insure I get the right results, but it surely is fun making sure it shoots correctly. 😁

I use TriggerShims brand trigger shims for my revolvers. Thay have a great selection for lots of different models.

 

I just went through this with my new-to-me 2015 2.25" DAO SP101 this past weekend. As recieved the trigger was 8.5 lb and really quite acceptable. However, I wanted to go through it myself. Polished all contact surfaces and lightly used slick 2000 on them. Added shims to both hammer and hammer dog (both had .016 slop). Replaced the trigger spring with 8 lb and tried trigger. Smother and maybe down to 8 lb pull. Trigger seemed to return fine with reduced spring I then started changing the mainspring. Put the 12 lb in, 11 lb trigger pull, 10 lb in, 9 lb pull, 9 lb spring and 7.5 lb trigger pull. My assumption is that the spring in the gun when I recieved it was a 9 lb, or close. The work that I did dropped the trigger pull by about 1/2 lb. Of course, to me it seems smoother too.

Now I am well aware that this needs to be extensively tested and I am not done. I have fired ~30 38 spc with cci SP primers, 10 357 with cci SMP primers, and 30 commercial rounds all fired without trouble. The gun shot well, but I have a tendency to pull left and down. Need dry fire and ball and dummy practice. When I did my job the gun was right on target at 10 yrds.

I think the work you are doing is important for you to know the gun and have confidence in its condition. It least it is for me. Good luck.

 

Aside from the MCarbo video another online source of tuning the SP101 is:

Ruger SP101 Trigger Job Guide

 

another online source of tuning the SP101.

That's a good one, worth the time to bookmark.

 

I had poor results on my old SP101 .22 6 shot with the Wolfe Spring set for the SP101. FIrst time I was ever disappointed with Wolfe. A quick second shot often hung up as trigger would not reset, and I had some light strikes. I went back and took out the springs and smoothed up the sides of the trigger and hammer, and cleaned and used a different lube, but did not touch the sear. It was much smoother and worked well with the stock springs.

However I suspect YMMV, and it is possible the old windage-only .22RF 6 shot versions versions are slightly different. I do like that revolver.

 

I had poor results on my old SP101 .22 6 shot with the Wolfe Spring set for the SP101.

I also encountered problems with Wolfe spring sets on SP101's. Dropping spring weight, without cleaning the "snags" and burrs out in the grip and frame where they operate was the cause. The lower weight springs can work, but not if they are fighting to overcome the rough edges on the internals. No matter what I tried, the lowest weight spring combinations are not for anyone that can, or needs to operate DA at a very fast pace. My fingers were barely fast enough to encounter that about 30 years ago or so, when they first came out.

My original 3" SP101 turned into a 4" model with adjustable sights, and went home with my oldest daughter. there are currently 4 SP101's in the family, including two .22 rimfire' 4" with adjustable sights. They all needed to be deburred and polished to work well with various combinations of Wolfe lower weight spring sets. The OEM springs never fail.

SP101's are not really unique in that respect. I'm not sure how many Ruger revolvers there are in my family, single action, and double action, centerfire and rimfire, but they all have Wolfe springs for the triggers, most have lower weight hammer springs, all of 'em have had their innards polished, (not filed, ground, or stoned aggressively). The process is not necessary, but the triggers are a lot smoother, and DA operation takes less effort. I think the most significant upside to Ruger designs is that mechanically, anyone with a bit of instruction and common sense can maintain and improve performance of a firearm, without a trip to a gunsmith.

 

After taking a stone to one of our two SP and GP I don’t understand the need for a lighter spring. I love the SA and DA on ours. Very predictable and don’t worry about light primer strikes.

 

Exactly! @Bill in VA