I just shot a box of 50 this weekend with the 11lb hammer spring without issue, next time out I'll swap it for the 10lb, not sure about the 9lb though...

 

Hey Q1 - I'm a helpful guy too. I'm more the buttermilk of human kindness....

I've put the lightest springs in the Wolff shooters pack in several GP100s (SP101s too) but that's after I went through all the tips and techniques in my handsome, spiral bound, limited edition, first printing copy of Iowegan's Guide to the GP100/SP101/Security Six. After investing a lot of time in polishing the right surfaces and removing all the grit and debris left from manufacturing I have some very smooth, very light triggers without any light strikes/failure to ignite. Some of my efforts have better results than others but that's part of the fun too. None of these guns are for personal or home defense - all range guns - so I'm comfortable pushing the envelope a bit with the lightest springs.

Try 'em all out and see what you think. But springs alone are not always the answer to get you the trigger you want. Spend a little time polishing/buffing/de-burring too. Lighter springs can make a gritty, hitchy (is that a word?) trigger feel worse.

 

I put in the 12 pound main spring and the 8 pound trigger return spring. It's pretty light and I'll probably switch to the 10 pound trigger return spring and go back to the stock main spring if it becomes my primary defense weapon.

 

I used a 12lb hammer and 10lb trigger spring in my GP100. Also polished the trigger and hammer touch points. Made for a very nice setup, still slightly heavy during DA pull but wonderfully light for SA work.

 

12# hammer and 10# trigger return springs, then shimmed hammer and trigger, with a lot of dry fire. Batter than my action tuned SP101 from about ten years ago. I'm not going any lighter on the springs.

 

I polished everything in my Gp100 and tried different springs at the same time. I ended up going back to the factory springs because the trigger was too light in single action mode. With the factory springs and a complete polish job, SA trigger is 3 LBs. I polished my brothers GP100 and the SA trigger was still too heavy. I put in a 12 LB hammer spring and it got much better, 3.5 LBs in SA and about 7 Lbs DA if I remember correctly. Every gun is going to be slightly different. I would just try out several spring combinations until you get what you want. I recently got a SP101. I did a complete polish job on it and it made very little difference. It smoothed up but is still very heavy, esp in DA. Almost need two fingers to pull that trigger. I tore the tendon in my thumb a few years ago. The hammer is so hard to cock on the SP101 that after cocking it about 20 times it starts to hurt my thumb. I will be trying different springs with that soon.

 

I installed 12# hammer and 10# trigger Wolff springs in my GP as well as polishing mating surfaces in the trigger and hammer group. The DA is very nice now, and the SA breaks like glass.

 

I'm running the 8 lb trigger spring and 10 lb hammer spring in my 5 in bbl GP100. I have not done any polishing of the internals, only a thorough cleaning and lubrication when new. It is a range gun, and I only shoot 38 special handloads. It has an extremely smooth action and I have had no problems at all.

 

I've gone with the 10# hammer and 8# trigger in several of my GP100s. The only negativity I've had is one had a slow trigger return and one gave light primer strikes. I did take the burrs of the hammer strut and cleaned up the area where the trigger spring goes in but that's about it. Live Wave said you're going to have to try it and see. In my SPs I've pretty well settled on the 9#trigger and 8# hammer.

 

I prefer the 10# set straight through...9# hammer spring doesn't always deliver enough 'punch' to do the job...depending on the ammo!

 

Great thanks to each of you for your responses. I appreciate them. Many commented there's not a one-size-fits-all answer so I guess a little experimentation is in order. Since this will be basically a range gun and I'm partial to very light triggers, I guess I'll begin with the 10# hammer and 8# trigger return. I'll see how that works out and go from there.

Wave, as far as I can tell Iowegan's IBOK on the GP100 is no longer available. I "searched" it and see there were copyright issues so it had to be pulled. So, if you printed it out, you were fortunate.

 

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Wave, as far as I can tell Iowegan's IBOK on the GP100 is no longer available. I "searched" it and see there were copyright issues so it had to be pulled. So, if you printed it out, you were fortunate.

Just to clarify, I did not print out the IBOK. I am fortunate to own a published copy of the guide to the GP100/SP101/Security Six that Iowegan wrote, published and sold some years back. A family member purchased a copy from Iowegan and has since passed it on to me since I am more inclined to fiddle around with the internals of my Ruger DA revolvers. I treasure this handy book right alongside my copy of The Colt Double Action Revolvers by Jerry Kuhnhausen (a more recent discovery - can't have too many good gun books.)

I don't know if the IBOK is the same as my published Guide but I do seem to recall it was the proliferation of his copyrighted material appearing on other websites that prompted the removal of the IBOKs from this forum. The IBOK is copyrighted material and the intellectual property of it's author and if I recall from other threads here Iowegan has not given his permission for his materials to be "ripped and posted" all over the internet. Proceed with caution........

Back to your springs - you may want to pick up some shims as others have mentioned. Some triggers and hammers seem to respond well to a few properly placed shims. I have others that don't seem to really benefit and are well balanced side-to-side out of the box. If nothing else the process of replacing springs should reveal if you have any metal shavings, metal chunks or other debris that hung around from the manufacturing process. I've found this stuff inside many of my GP100/SP101s.

 

Edited

 

Here is the IBOK online
Ruger GP100 Book of Knowledge | Gunner's Journal

Hey! Thank you, partner. I searched high and low looking for this. Google was not my friend. But, you are.

 

Having both a SP and a GP have played with springs in both. Both have been tuned by gunsmiths and then I have fiddled with them a bit more and the 8 lb trigger return and 9 lb mainspring work in both. As Iowegan notes going to lower rate mainsprings increases lock time and the GP 100 with the lightest springs is similar to a tuned Python I used to have. As you are concerned with the GP with the lightest springs single action is 2.5 - 2.65 lbs and double about 7.4 - 7.5 lbs. A partial solution to the locktime issue is to use a lighter hammer. Randy Lee of Apex Tactical offers such for S&W ( see: https://apextactical.com/store/avactis-images/RevoN-FrameHammerKit.jpg as an example). Too bad he does not for the GP but once in an email he stated he thought for a range gun he could get the double action to the 5 lb range (his S&Ws run in the 4 lb range).

Aside from the lighter hammer one could add shims to reduce friction slightly, set head space to minimum and firing pin protrusion to maximum and lighten the mainspring further by using a different tension spring if you can find one or clipping some coils off of an existing spring. At one time Walt Sherman in Florida made roller double action sears for Pythons and the old style S&W K, L and N frames and had planned on offering them in GPs; unfortunately, he switched from gunsmithing pistols to rifles. His range guns Pythons worked at 4.5 lbs DA and I had a carry one that ran at 6.5 lbs DA. So, there are possibilities for the future.

 

Good stuff, Rover. Thank you. I just finished installing the 10# hammer and 8# trigger return. My cheap gauge shows quite consistently a SA pull of 2 lb. 12 oz and the DA at about 8 lb.s 4 oz. The "proof in the pudding" will be when I get it to the range. I'll post a range report when I do. Right now I'm waiting for a set of William's Fire Sights to arrive. I figure there's no sense dialing it in twice.

(I'm planning to install hammer shims but that will be after I shoot it a bit.)

 

I found general opinion is that each gun might tolerate the light springs a bit different. This is mostly due to different friction factors built into every gun depending on fit and finish. The actions can be significantly "tighter" from one to the next and only the IBOK can help you understand how that comes into play. Never heard anybody having consistent luck with spring lighter that #10 for what it is worth, results may vary.

 

I'm really looking forward to a range report on your revolver with the spring setup that you have installed. As Wave has mentioned, these revolvers do seem to vary as far as need for shims, and how they respond to different weights of springs etc. I really got lucky with my current GP, as it was pretty darned nice right out of the box, and the spring changes and considerable dry-firing got it spot on. I have been in the market for a 3 inch GP and have been handling several at gun shows, and have literally been amazed at the difference from one to another as far as action and trigger pull.

 

I swapped out the hammer spring for a 10lb and ran over 50 rounds of various factory and reloads. 100% first hit ignition. Very happy with the setup.

 

Glad that weight worked for you.