Good job! Sounds like you had fun and learned a lot in the process. Report back on how it shoots.

 

Glad you took the time to do more than just swap springs. I think you could have gone down to an 8# trigger spring. I have two GP100s with a 12 & 8 combination, shimmed and polished, and get just under an 8# DA trigger pull on both of them. If you get around to installing the 8# trigger spring you should remove the "trigger link plunger" that fits into the far end of the trigger spring and then hand turn a 13/64" drill in the hole to break free any burrs that might be in there. The hole is little bit larger than the spring so polishing inside the hole is not needed, but you don't want a burr. I found a small burr in one of my GPS, so it does happen, but if you don't don't find one easily, don't go digging around looking for one. Again, good job!

 

Doesn't it feel good to work on your own guns? Enjoy shooting your revolver and making sure it works reliably with your favorite ammo.

 

Indeed!

Doesn't it feel good to work on your own guns?

 

I had one GP100 that would not cycle reliably with an 8 lb trigger return spring while my second one would not. Part of what I like about the Ruger double-action revolvers, it is easy for someone with decent mechanical ability to do some spring changes, add shims and come up with a pretty decent action.

 

I had that same problem with one of mine, but the gun had other problems so it went back to the factory. After that I polished the Trigger Plunger and the Cylinder Latch. 8# spring works jsut fine now.

 

I recently switched out my 11# Wolff hammerspring and 8# Wolff trigger return/triggerguard latch spring out for a set of ISMI chrome silicon springs, which are approximately 12# for the hammer spring and probably about 11# for the trigger retrurn/triggerguard latch spring. Despite a previous very thorough action job (among other improvements), the triggerpull with the Wolff springs provided a somewhat stagy pull.

In dryfire, the ISMI spring set seems to significantly provide a smoother, less stagy triggerpull than the Wolff springs provided-almost as good as the pull on my Security Six. I'll be using it in an IDPA match on the 18th, using full-house 158 gr .357 magnum. Although the nominal pull weight is heavier than that of the previous Wolff's, the pull feel of the ISMIs seems lighter (in addition to being significantly smoother); that may be due to the different structural/material/treatment differences betwen the ISMI and Wolff.

My GP100 has been throughly gunsmithed by an eminently qualified and nationally respected gunsmith, so it's a great proving ground to take advantage of superior springs; I'll see how they perform in actual live fire use and hold up over time.

Best, Jon

 

Took my GP100 to the range today, fired 50 rounds of Geco 158g FMJ, 1/3 are DA, 2/3 are SA. No misfire with #12 hammer spring as expected!
Now my DA's accuracy is as good as SA's, although my DA's pull is slower in order to get good accuracy.

I'll shoot more and get a pull gauge to measure the DA pull weight. ( 38/357 is so scarce nowadays...I was lucky to bought some before the pandemic. )
Then follow CtYankee's suggestion to further check any burr in the hole for trigger return spring.
Maybe I'll try #8 if it doesn't affect trigger reset.

There are so many good springs set out there, Wilson Combat, ISMI, MCarbo...
Finally, I just chose the most popular one based on the review from Midway USA.
Good thing about Wolff springs set is you can always switch springs!

Thank you all for the good comments and sharing!

 

Finally, I got the wheeler digital gauge to test the pull weight.
DA ~ 8 lb 8oz
SA ~ 3 lb, I am surprised it is at 3lb, it feels pretty light

For your quick reference,
polishing ($11 stone) +
hammer/trigger/hammer_dog shims ($15) +
12lb hammer spring + 10lb trigger return spring ($10 wolff)

 

Don't you just love it when a plan comes together?

 

There is some (valid) complaints about GP100 trigger pull. But for a few dollars and about 1½ hours of bench time you can tune the trigger up pretty well and you learn a lot about how your revolver works and goes together. I've always found it satisfying.