Picking up a ruger gp100, trigger job info?


December 2, 2013, 12:11 PM
Picking up a ruger gp100, stainless, 6". Doesnt even have a turn ring. I'm going to want to lighten and smooth out the trigger to butter if I can. Would love a 7-8LB DA and a 3LB SA if its possible.

I hear the wolf spring kits work wonders. That and some light stoning of the internals to remove burrs makes all the world of difference in these guns.

Does anyone have any info on what the factory trigger pulls are DA/SA and what the trigger pull weights are with the wolf kit installed (and which hammer spring you are using.. 10, 12, or 14 lb)?

Thanks for the info.

Also, anyone using the weigand no D/T scope base that would care to give an opinion? Looking to use this thing as a deer gun in VA (30-40y shots.. I'm confident I can hit with irons, but I'm more confident with a scope and I want a clean, humane kill).

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December 2, 2013, 01:54 PM
Stock double action pulls seem to range about 10.5 to 12 lbs and single action in the 4 lb range. On my GP100 with an action job and a 8 lb trigger return spring and 9 lb mainspring the double action pull is 7.4-7.5 lbs. and single 2.75 lbs. Here are a few links to improving the trigger:




on adding shims to the action:


on firing pin protrusion if needed:


sear engagement theory:

evening out the trigger pull if needed:

I don't think you will need all of them. A number of users find to get reliable double action ignition on CCI primers that they need to use the 10 lb mainspring. What works is a function of the smoothness of the action and tolerances of the individual gun. Hope this helps.

December 2, 2013, 05:55 PM
Try either of these:


The Brownells kit is probably a Wolff kit anyway so it really doesn't matter which you buy.

December 2, 2013, 06:19 PM
thanks rug and arch. I'm looking at IBOK now..

December 2, 2013, 06:44 PM
I use the Wolff springs in all my S&W's and Rugers. The rebound or trigger return spring is the one to change and not affect ignition (light primer strikes) Changing the main spring does very little to reduce the trigger pull.

Try just the spring first before you go stoning or polishing parts. Advantage of the Ruger is it is very easy to take apart

The Weigands mounts are the best regardless of gun you put them on.

Buy springs direct from Wolff, they make them for almost everyone as OEM parts.

For a hunting gun, leave the mainspring alone, You can get the shooter pack and experiment but I have several guns the reduced spring will work some they will not, Factory is 14 lbs

The return spring you can put the lightest one in unless you are speed shooting and your finger is faster than the return,:)


December 3, 2013, 03:16 AM
WARNING, it's not a good idea to stone MIM parts because they are very soft but for the hardened outer surface. If you break through the hardened exterior surface the part will fail in very short order.

December 3, 2013, 04:49 AM
Arch.. I wasnt aware that ruger was using MIM in their revolvers.. Everything I've heard so far was that they were using cast... Is this information out dated or incorrect?

When did they start using MIM if they do use it, this revolver may predate that change.


Been browsing since I posted that comment..
Yes, the Crane latch, cylinder latch, front sight. - These are the MIM parts that ruger admits to using MIM in as far back as 05/2011. The hammer and sear are about the only places I'd do polishing.. and thats very light anyways.. more about removing a bur than actually removing material across the whole surface.. 1-2 drags across a 1k grit stone usually suffices.. I'll definitely be double checking parts though before I do any stoning. Appreciate the heads up.

December 3, 2013, 10:28 PM
emailed ruger about it.. they say the only parts that are MIM in the gp100 are the cylinder release and the trigger.

Thanks again for the heads up archangel

December 4, 2013, 06:50 AM
just the information I was looking for

December 4, 2013, 07:25 AM
and the wolf spring kit is in the mail..

jolly roger
December 4, 2013, 08:43 AM
Just picked up a 5 inch GP. Put Wolff springs in it both 10 pounders. Leave the stoning alone IMHO. the 10 pound springs are fine and it has smoothed up considerably over about 500 rounds of 38-357 already. Just shoot...

December 5, 2013, 04:01 AM
emailed ruger about it.. they say the only parts that are MIM in the gp100 are the cylinder release and the trigger.

Thanks again for the heads up archangel
I wasn't saying Ruger used MIM parts in the trigger assy, it was just a general warning since I know S&W does. I wasn't sure about Ruger so I made a general warning just to be safe...

Thanks for contacting Ruger and getting the correct information.

December 5, 2013, 05:10 AM
Turns out your general warning was beneficial to the overall knowledge of the group... Thanks man.

December 5, 2013, 12:50 PM
Ruger has been using MIM parts here & there for well over 10 years.

But, the info on surface-hardening is wrong.
That's the true non-MIM case-hardened parts like S&W used to use.

MIMs are through-hardened, there's no problem whatever in stoning Ruger's MIM parts.

Side note- the SP uses MIM trigger & hammer.
Ruger decided the MIM hammer in a GP would look too ugly, so for now they're sticking to a cast hammer in that gun.


December 6, 2013, 05:38 PM
Also, anyone using the weigand no D/T scope base that would care to give an opinion?

Best thing I did to my GP was adding that base & a Ultradot red dot...30mm

http://i1126.photobucket.com/albums/l613/groundsclown/photo1-1.jpg (http://s1126.photobucket.com/user/groundsclown/media/photo1-1.jpg.html)

http://i1126.photobucket.com/albums/l613/groundsclown/photo2-2.jpg (http://s1126.photobucket.com/user/groundsclown/media/photo2-2.jpg.html)

Next to my 4" GP

http://i1126.photobucket.com/albums/l613/groundsclown/photo4-1.jpg (http://s1126.photobucket.com/user/groundsclown/media/photo4-1.jpg.html)

December 7, 2013, 02:06 PM
I have a 5" bbl GP100 that I bought new and was made in December 2010, this was before they started using the MIM trigger. Honestly, all I did was strip the trigger group, thoroughly clean and lubricate, and install a Wolff 8 lb trigger spring and 10 lb main spring. I spent an evening of dry-firing, and it is smooth as butter and absolutely perfect.

December 7, 2013, 02:41 PM
About 18 months ago I got one of the last standard GPs with both cast hammer & trigger.
The one that arrived two weeks ago has the MIM trigger.

Both cast & MIM will smooth up with use, but it's entirely safe to stone either type in shortening the "natural" polishing interaction process.

December 7, 2013, 03:09 PM
Do not swap the trigger return spring. I installed the 8# spring and it is too slow for speed shooting. I was able to get down to an 11# hammer spring and get reliable ignition with trigger shims. However, I think it is better to leave the factory springs alone and merely polish the internals and use trigger shims.

December 7, 2013, 03:51 PM
You may want to shoot the gun for a while, including lots of dry firing, to see how it smooths out. I have guns with action jobs and lighter springs that aren't reliable with all ammo. I bought a GP100 5" about six months ago and I dry fired it 1,000 rounds before I shot it. After a couple of trips to the range and about 200 rounds fired, it is almost as smooth as several well worn S&W's that I also shoot. I have had two GP100's and they both have smooth actions without any modification. I think Ruger does a better job in recent years, as far as smoothness of actions. See how yours actually works before modifying it unnecessarily.

December 7, 2013, 05:23 PM
Larry, is not just about smoothing things up, is also about lightening the trigger pull a little bit.

December 7, 2013, 05:24 PM
Smoothing the surfaces does help lighten the pull, both DA & SA.

December 7, 2013, 05:33 PM
Exactly Dennis. But even that may not be enough for me.... I'm a self admitted trigger snob. Heaviest trigger in the safe is 3.5 lbs, and that's on a milsurp rifle. I really like my handgun triggers to be 3lbs or a hair less.

December 7, 2013, 07:26 PM
Good luck with it.
Newest one here's slightly over 4.5, it'll lighten some with wear & I'll probably let it age naturally. :)
I don't change springs on GPs, I require absolute reliability.

December 8, 2013, 07:48 AM
My first GP100 had light strikes with a mainspring of a now-forgotten brand, so I re-installed the factory mainspring. The slightly lighter trigger return spring is still in place. I did stone the surfaces VERY lightly, and changed NO angles. I wanted absolute reliability. I carried this one, and had to shoot it once for blood.

Since that first one, I learned to cherry-pick my DA Ruger revolvers, because some of them need no work whatsoever, just a bit of dry and live fire to smooth things nicely. The one exception was my 5" GP100, as it was from a limited run, with one at the dealer, and no more at the distributor. It has a gritty trigger stroke, which I may remedy someday, unless a collector persuades me to part with it when I am in a down-sizing mood.

December 8, 2013, 11:51 AM
The trigger action on every GP100 is different from one gun to the next. That is why most aftermarket trigger springs are sold as a kit of various weight springs. The shooter can experiment and see which works best for their particular revolver, and will give them the results they want for the intended use of the revolver. In my case, the 8 lb trigger return spring worked very well. It resets as fast as I can possibly release pressure on the trigger. Having said that, my GP100 isn't my personal protection revolver, and the ones that serve that purpose remain intact with all the factory original springs.

December 8, 2013, 12:04 PM
I bought a 2013 production 3" GP100 this year...it has one of the best revolver triggers I have ever experienced. Both DA and SA are better than my two older, well used S&W's, a Model 15 and a Model 10.
I had read up on spring changes and stoning parts on the GP...I won't be doing a thing but shooting it.

December 8, 2013, 12:49 PM
Again- no problem whatever in stoning MIM parts, if you're concerned about that non-existent issue.
I don't know where that originated.

Old Fuff
December 8, 2013, 01:38 PM
You can polish/stone MIM parts, but if you simply dry fire the revolver the contact points between parts that are under pressure (usually caused by spring tension) will burnish themselves smooth.

They're at least two possible negative to removing metal:

1. Take off too much in the wrong place, and the part(s) may become out of tolerance.

2. If for whatever reason you return the revolver to the Ruger factory and they discover aftermarket "polished" parts they are likely to replace them and bill the owner for the replacements; or return the gun and refuse to work on it. Burnishing on the other hand won't void the implied warrantee.

December 8, 2013, 02:17 PM
Since its a used revolver, no warranty

Trigger feels ok, no grit to polish out. That wide & flat trigger i dont like. May have to get a spare and reprofile it a little to be more rounded on the right side.

Looks to be an 07 production. If the trigger is mim, i cant tell. Same with cylinder release

December 8, 2013, 02:21 PM
Now to get rid of those aweful sights. Not sure if shell get an optic or fiber optic irons yet.

December 8, 2013, 03:10 PM
If it's an '07, it won't be MIM. That started less than two years ago in the GP. MIM triggers on the GPs & SPs are very easy to tell anyway- if the back is solid, it's cast. If it's hollowed vertically, it's MIM.

And, good luck on getting a spare trigger. :)

December 8, 2013, 03:32 PM
I have a couple smiths that may oblige... Finding an all steel one, that may be harder

December 8, 2013, 04:41 PM
An obliging all-steel smith? :)

December 8, 2013, 06:45 PM
I have a couple smiths that may be able and willing to order a new trigger from ruger.
Finding an steel trigger vs. MIM (yes, I know MIM is steel, but you know what I mean) would be a bit more difficult.

I've got a machinist buddy or two that could duplicate it though, but it'd not be cheap..

December 8, 2013, 07:28 PM
Dunno if Ruger has any of the pre-MIM triggers left, but you can always try.

December 8, 2013, 08:47 PM
I doubt the do... If have to get a mom one fitted
But first, trigger return spring swap

December 10, 2013, 09:06 PM

And here she be

December 11, 2013, 05:33 PM
Since its a used revolver, no warranty

Trigger feels ok, no grit to polish out. That wide & flat trigger i dont like. May have to get a spare and reprofile it a little to be more rounded on the right side.

Looks to be an 07 production. If the trigger is mim, i cant tell. Same with cylinder release

Don't worry about MIM, if you do then you will worry the whole gun is cast;) Change the springs shoot it a lot and it will feel fine,

December 11, 2013, 07:47 PM
2. If for whatever reason you return the revolver to the Ruger factory and they discover aftermarket "polished" parts they are likely to replace them and bill the owner for the replacements; or return the gun and refuse to work on it. Burnishing on the other hand won't void the implied warrantee.

My personal experience with sending my GP100 back to Ruger in 2009 says this statement is un-true.

I did a full on trigger job, replaced the springs and then had a problem with one of the parts I had worked on being out of tolerance and the cylinder bound up.

I could not even swing the cylinder out of the frame and could not pull the trigger.

Ruger replaced one part with a new part, left all the other parts alone and sent my revolver back to me.

Ruger did not even charge me for the part.

Personal experience.

December 11, 2013, 08:56 PM
Rule, we have all live through an 07... 2007 lol. Also, im not worried bout mim... Dont mean i want it. Cast = one piece poured into shape... As strong as the extruded bars most guns are milled from.

Mim= sintered metal powder, so far different it hurts to even try to intimate they are even related

December 11, 2013, 09:26 PM
Sintering was actually a much earlier predecessor to MIM, similar process but different.

I think it's fair to say that properly done MIMs are markedly superior to sintered parts.

December 12, 2013, 12:15 AM

December 12, 2013, 06:00 AM
Dpris - my understanding of MIM is off then. I understood it to be metal powder and a bonding agent injected into a mold that is a little larger (roughly 25-30% larger depending on the piece) and then heated to sintering temps in order for the metal powder to bond to eachother. There is a bit of shrinkage due to the this...

I'm guessing I'm pretty far off base on that. Even if that were an accurate description, I dont have a problem with MIM in and of itself.. I just dont think it should be used in friction parts against hardened steel. Low stress parts, non issue. In this revolver, where the trigger also acts directly on the hammer.. I'd not care for it so much, but I could see it being doable (or ruger, smith, etc.. never would have even bothered to attempt it).

Old Fuff
December 12, 2013, 11:09 AM
I think it's fair to say that properly done MIMs are markedly superior to sintered parts.

I'd agree, but I'm not so sure they are better then high-quality investment castings that Ruger was (and is) famous for. The primary reason the firearms industry is going to MIM technology is cost savings.

But now it's a moot point. The future is clear.

December 12, 2013, 01:27 PM
You're now describing MIM.
Sintering doesn't use the binder.

Saying MIM parts are created with sintered metal is not entirely correct.
Both processes use powdered metal technology, but the processes are not the same.

I agree with you, but I wasn't going to start up the whole MIM controversy again.

Old Fuff
December 12, 2013, 02:11 PM
... I wasn't going to start up the whole MIM controversy again.

Unquestionably a good idea, but they're shouldn't be any controversy. MIM parts are a done deal.

Those that have a problem with MIM technology have the option of buying earlier made guns. Those that don't care can buy anything they like. ;)

December 12, 2013, 02:32 PM
Agreed guys.

Dp, i think the difference is picking nits. I was using sintering as a reference to heating a metal to a temp hot enough to cause bonding without melting... Not the manufacturing process. I dont have an issue with mim, but id rather keep it to firearms that shipped with it.

December 12, 2013, 08:05 PM
Not nitpicking at all.
Sintered parts & MIM parts are not the same & the process is different.

If you refer to MIMs in talking about parts, you don't use the term interchangeably with sintered, or say that MIMs are made of sintered material.

Both are powdered metal processes, but MIM is not sintered & sintered is not MIM.

December 13, 2013, 07:31 AM
so you're saying that the final method of forming bonds in the metallic powder is NOT sintering for MIM? That bond is somehow different than if I were to take metallic powder, heat it to temp and then layer it? Is the density different, metalluligically they are the same. Are the bonds between the particles of powder stronger because it was sintered after removing the bonding agent in MIM vs. tratditional sintering? I wasnt using the terms interchangable.. But yes, a MIM part is made by sintering powder together.. so that part IS sintered. The method to get it into shape doesnt change that fact. It may change the end outcome.. but not that much... Lets not forget DLMS is just sintering too and they've made a fully operational 1911 with that recently (and it has several hundred rounds down it in testing). With that in mind, I dont consider it inferior, but it also isnt my prefered option if I have the choice. Sintering is the method used to get the metallic particals to bond.. if you only use it to describe one specific manufacturing process, you may be right from the standpoint of process.. but my use was not incorrect.

If MIM isn't made of sintered material, what is the final step? Is it NOT "the welding together of small particles of metal by applying heat below the melting point"? From everything I've read on MIM.. that is exactly what is happening.. so MIM, by the definition used in the encylopedia britannica.

The other definition that bing dictionary gives up is "
1.bond metal particles: to use pressure and heat below the melting point to bond and partly fuse masses of metal particles, or be bonded in this way
2.bonded metal particles: a mass of metal particles bonded and partly fused by the use of pressure and heat below the melting point

If dictionary.com is more your flavor (left off definition 1 as it doesnt apply to the use here) :
2. Metallurgy . the product of a sintering operation.

verb (used with object)
3. Metallurgy . to bring about agglomeration in (metal particles) by heating. "

or Merrium Webster:
Definition of SINTER

transitive verb

: to cause to become a coherent mass by heating without melting

intransitive verb

: to undergo sintering "

That also seems to be a dead ringer of the final step (The bonding agent is stripped out before this occurs in MIM, so the process itself is more detailed, but to say its NOT sintered material is inaccurate). Basically I'm saying, dont get caught up in how one industry uses a term, especially since there are other uses for the exact same word that can and may apply. Shoot, the first time I heard the process described, it was by a journeyman machinist.. who used the phrase "sintered together" for the last step.. which I then had to have explained since I wasn't familiar with the term.

December 13, 2013, 07:41 AM
In both processes, the materials start out in powdered form (sintering without binder and MIM with a binder agent) and are based on powder metallurgy. However, traditional sintering uses pressure and time to create diffusion and binding and MIM uses mechanical diffusion of the powders (premix with binders and agents) and a near-melting heat step to complete the finished form.

If you define sintering as the process of using diffusion to mix and bind the powdered metals (the traditional 'sintering' process complete), then MIM is not sintering. If you define sintering solely as the process of using heat (among other things) to form a powdered metal into a single solid, then both are examples of sintering.

boom boom
December 13, 2013, 10:25 AM
Both Patrick Sweeney in his Gunsmithing book on handguns and Grant Cunningham in his revolver book have some pointers on GP 100 triggers. Grant has his own blog so you might shoot him this question--especially in regard to MIM triggers which I don't believe that either one addressed.

December 13, 2013, 10:40 AM
boom boom, thanks for the heads up.

I've a cast trigger, so I'm not worried about it. I'm not sure getting the trigger reprofiled to fit my personal tastes is high enough on the list to go and have a spare fit to the revolver just so I can reprofile the trigger... I wont do major modifications (even ones that are purely cosmetic) unless I can reverse them..

December 13, 2013, 12:29 PM
As mentioned earlier, the processes are different & MIM is not traditionally referred to as "sintered".

If you want to blur the lines in discussing it, that's up to you.

As far as altering the cast trigger goes, I've had that done on three GPs.
The cast triggers came with sharp edges on the rear & I had those removed along with rounding the faces to meet my preferences.
I'll eventually have the same work done on two others.

The newer MIM triggers don't need either work, they have no sharp edges behind & they're more rounded up front.
Fine as they come.
At least- on this newest one here, if its representative. This is the first GP I've had with a MIM trigger.
So far, all MIM Ruger GP & SP triggers I have do not have the sharp edges, at the very least.
The SP MIM trigger isn't quite as rounded on its face, but I see no need to alter either of my two SPs that have the MIM trigger.

December 13, 2013, 09:21 PM
Just got an email from a Ruger contact.
The rounded MIM trigger face is standard across all new GP model variations.

One benefit to the introduction of MIMs in the GP. :)

With that already done & the sharp rear corners eliminated, all you may want to do on a newer GP trigger-wise is either stone it a bit or let it smooth up gradually in use.

December 13, 2013, 09:33 PM
D.. depends, but probably right. Its the expense of having it fitted properly by ruger that I dont know if I intend on spending.

December 13, 2013, 09:40 PM
I have an older 3-inch GP with altered trigger & de-horned hammer that had a good trigger job done.
Quite nice.

The action work was originally done as part of a light package at a custom operation.
Shortly after, it developed a hitch in its git-along on closing the cylinder caused by a factory-restricted part going bad (NOT a result of the action work).

Gun had to go back to Ruger, who promptly removed the trigger & hammer and replaced them with stock parts to return the gun to factory specs while they had it, completely undoing the action job.

Had to have that re-done locally.

Sometimes they'll leave things alone, sometimes they won't.

December 14, 2013, 09:53 AM
DPris, just curious, what was the factory restricted part that went bad that caused issues with closing the cylinder? I haven't heard of a similar issue before.

December 14, 2013, 01:26 PM

Old Fuff
December 14, 2013, 09:19 PM
At the time the "New Model" Ruger single actions were introduced the company offered a free conversion kit that would allow a transfer bar safety instalation in an older S.A.

As part of the deal the original parts were to be returned with the modified gun so if the owner decided they prefered the older style they could go back to it.

The conversions are still being done, and they are still free, but the parts that are replaced are no longer being returned. :uhoh:

If you have (or have had someone else) polish the internal parts, and you return the gun to Ruger for any additional work, don't expect you will see them again. You may, but it's doubtful.

Blame it on the lawyers.

December 21, 2013, 12:56 PM
well, I went to the 8 lb trigger return spring.. HUGE diference in pull weight. I did swap out the hammer, and I intend on using the lightest one that gives me reliable ignition.. being a reloader I can use softer primers if need be. I went with the middle of the pack, the 12 lb in there right now.. That should be enough, but if not, I can always go up from there 2 levels (the 14 and the factory which is 16 lbs right?). Trigger is noticeable smoother, which is odd, must be some roughness that could be worked out but I'll leave it be for now. Much lighter, more where I like it. Its hard for me to find a handgun trigger acceptable, the trigger I spend the most time is a bench rest trigger.. so all other triggers feel horrendously heavy to me.

December 21, 2013, 12:58 PM
good info old.. I find it acceptable at the time being.. I may get more picky or grow to like it more so I'll leave it as is for the time being.. until I see if it gets reliable ignition with cci primers at least.

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