M*CARBO Brotherhood

Ruger SP101 - Polishing Internals

Just finished doing a complete trigger job on a Ruger SP101 today! Replaced Springs, added shims, polished all internals and even lapped crown. Double Action Trigger pull went from 10lbs to 4.75lbs. Buttery Smooth Action Now! Really impressed with how different it feels…not even close to the same firearm.
I think we could start incorporating more internal parts polishing in our “how to” videos after seeing the massive impact this combination had.

No sanding just polishing like we’ve all done on our SUB2K Stainless Steel Feedramps.

This is all part of the New SP101
Trigger Job Installation video that will be released tomorrow.


You’re a machine @ChrisNelson. Good work!


YESSS!! :clap: A polished trigger is a happy trigger lol :smiley: :+1:


@ChrisNelson Waiting for the new video :smiley:


Thank you very much much sir. Just in time Tomorrow my spring kit kit will be in.


Got lucky and package arrived today. Already installed Win Model 70 trigger (Great job and great video). And started polishing my dads feedramp. Going to hold off for Chris to post video for SP/GP trigger spring kit. Can’t wait dermal battery is back on charger ready for the how to. Thanks in advance.

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Yes back to work I go :smiley:

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I started my SP101 project today. I ordered the kits, polished the internals, added the shims, added grease and installed the springs per the video. I only lost 1 lbs. I am at 9lbs 8 Oz… I am not sure where I went wrong. Any advice would be appropriated. On a more positive note. It is def a buttery smooth 9 lbs 8 Oz!

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just did my SP101 22 this week - the Wolff trigger and hammer spring set (‘pack’) is inexpensive and a definite improvement - however, although lots of folks complain about the heavy trigger pull of the rimfire SP101 (which is almost necessary), i didn’t find it too objectionable

but a new 13lb hammer spring has certainly lightened up the pull… i didn’t mess with trigger aside from the reduced trigger (8lb) spring

pretty easy and a nice upgrade!

on the ‘plinking away every day’ Gulf of Mexico

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I finally last night got the chance to finish mine install and polish on my Gp100 @GrizzlyPatriot I also didn’t end up with the same low trigger pull as Chris but my Double action is very very smooth and my single action well that lighted up a good bit. I don’t currently have a trigger pull gauge but just from knowing how it was to what it turned out to be what a difference.


@Doitsouthstyle nice gun, I am happy with how smooth mine is fore sure. It’s was a great learning experience.


Me and a buddy took mine out along with a few other toys. And she was definitely smooth and on point. He is new to guns and was amazed at the single action compared to the double. Good day off of work.

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I also completed the SP trigger job. While it’s certainly much smoother…trigger always felt gritty…I experienced no reduction in pull. 11 lbs before & after. I’ve got the SP without hammer spur but can’t imagine that would make a difference. Any suggestions would be appreciated.

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Happy camper! 5 pulls average is now 4.7# (factory 9.3#)! Smooth smooth pull, thank you!!!

BTW, mine is a SP101 in 9mm… factory new, still UNFIRED after I took it home. Will only get better as it accumulating range time.

Just to share, adding hammer shims was the most frustrating step in the whole process, but it is possibly just me…

Thanks, Chris!


Awesome! I’m really happy to hear this. Some of the initial results in this thread were starting to make me nervous. There will certainly be a good amount of variation depending on how much polishing you do. I’m glad to hear you got about a 50% trigger pull reduction!


your SP101 trigger kit is how I found this forum - mine is still on the way
have one of the first 1000 SP101 ever made back in '89
been sitting in the gun safe for 30 years due to the poor trigger - 14# double action
will keep you updated



Oldmanonthemountain - you’ll be very pleased, I am.

I bought a SP101 around 1992, I wish M*Carbo kit was available, I wish I did not sell it (coz I could not shoot with that factory trigger).

And I wish the current production of SP was as nice as those back in the days…

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after 29 years, I sent mine back to Ruger for a once over, since the trigger was starting to stick intermittently
it came back just last month with new springs which measured at 14# on the gauge (Ruger didn’t charge me)
dropped in a set of leftover Wilson Combat springs from my GP100 build and dropped the double action to 10#
we sill see after the mcarbo kit and polishing.
when someone tells me they have a 9.5lb double action pull, I would have been very happy with that for the last 29 years!
the best Ruger trigger I have is on an old Police Service 6 purchased from Napa County Sheriffs back in '77
7# double - 3# single and the smoothest Ruger I own
I could live with that quality trigger on my SP101


finished polishing and installing springs and shims from the mcarbo kit today in my 1989 SP101
I’m getting 7.5# on double action and just under 3# single action
and no trigger drag on the frame
I’m very happy with this as compared to the 14# from the factory
not all SP101 are the same, not all will respond the same to polishing
my trigger is not cast like the one in the Mcarbo video
the biggest improvement came from polishing the surface under the cylinder pawl
many of the cast surfaces in mine were just too rough to polish out completely
maybe with stones I could get it better, but I’m happy with this performance
and over the last 29 years, I know I have more than 1000 trigger cycles
and it’s still much better than any S&W J frame I ever fired!