SP101 action

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jrtrapp1

Bearcat
Joined
Apr 30, 2006
Messages
29
Location
Alabama
I field stripped an SP101 last night. The DA trigger is horrible on it. When you first pull it back the cylinder begins to rotate (roughly 25%) then the action hangs up a little bit and you have to pull considerably harder to get it to continue then it rotates the rest of the way and fires. If you fire it slowly you can stay on target when the hammer drops but if you try to fire it in one motion it pulls way off target.

I lubed it up and when I went to put the trigger group back in I noticed that the group was etched with a 17. There is no 17 in the serial number that is on the frame. I always thought that the etched number was supposed to be the first 2 or last 2 digits in the serial number. Is this correct? Did Ruger get some parts swapped at the factory?

Now that it is oiled it is a little better but it still hangs up pretty good. I am probably going to have to find a smith to do an action job on it. I watched some videos on doing an action job on it. I can take it apart and put it back together but I do not feel comfortable smoothing the parts or diagnosing where it is hanging up.
 
Joined
Dec 17, 2015
Messages
2,377
Location
Reading, Pa
The trigger pawl plunger(inside the trigger group) or the trigger return spring/latch are where I'd go. Remove the latch spring from the bore and make sure it's clear and free, I actually had a broken trigger pawl spring on my .22lr 8 shot SP101which was the cause of the exact problem you describe.
 

jrtrapp1

Bearcat
Joined
Apr 30, 2006
Messages
29
Location
Alabama
Thanks for the reply. I would not think a new revolver would have a broken part but you never know. When I get time I will take the trigger group apart.
 

deac45

Single-Sixer
Joined
Mar 14, 2005
Messages
448
Location
NW Georgia
Check the lower end of the hammer strut to make sure it is not rubbing the frame at full travel. Mine always had a slight hitch in the trigger pull in double action just before the hammer fell. Finally noticed during reassembly once it was hitting the frame when fully cocked. a few file strokes cleared it up.
 

woodsy

Blackhawk
Joined
Jan 5, 2012
Messages
964
Location
Seymour, CT
jrtrapp1 said:
Thanks for the reply. I would not think a new revolver would have a broken part but you never know. When I get time I will take the trigger group apart.

When you do so, do it in a plastic bag. Don't ask me why.
And the SP's in general are not known for smooth actions. But if one performs the "Poor boy's trigger job" it definitely improves, because it mimics thousands of cycles without firing ammo.
 

silverback

Blackhawk
Joined
Aug 9, 2012
Messages
591
Location
el paso texas
Check out Mcarbo sp101 trigger spring kit video. Its long but provides the best in depth video i have ever seen for describing sp101 take down, reassembly part description and where to polish.

https://youtu.be/txbCmzM4v6A
 

noahmercy

Blackhawk
Joined
Jun 13, 2015
Messages
746
Location
Sheridan, WY
Quick and simple rule on where to polish is where you see drag marks, the chamfer on pin holes, the pins, and the hammer strut. I leave the factory hammer/ sear interface alone, and usually install a spring kit, so my triggers are smooth, light, and safe. My SP101 has a 10.5 pound DA and a 3.2 pound SA pull with no hitches or grittiness (albeit with some takeup and overtravel). Since it's not a match gun, that's just fine.
 

Thel

Blackhawk
Joined
Jun 22, 2010
Messages
639
Location
Pacific Northwest
Take a look at my reply in this thread:


My SP had the hitch you mentioned albeit not so badly.
 

173rdLRRP

Single-Sixer
Joined
Mar 17, 2022
Messages
199
Location
Colorado
100# pull. I will measure with bow string pull scale.

Have Crimson Trace on Taurus 605 and SIG 229 (.357 SIG). Finally looked at Crimson Trace video after I changed batteries and laser did not work. Commentator noted "make sure to now turn on master switch in base of grip" aha, the mystic on switch.

I find the Crimson Trace to be very effective in dry fire.The red dot now moves less than 1/4" with double action (it is DAO).

Both distal and middle phalanges of middle finger have to tightly grasp for the Crimson Trace to operate. I discovered I was relaxing middle phalange (laser dot went off). I am working on this so the grip is now far more firm. I do 50 or more presentations a day with five dry fires each time and 25 with 4" SP101. Trigger finger quits after that.

The Iron Mind TUG finger gripper for one or two fingers is excellent for developing f di usual finger strength. The Iron Mo d hand grippers are good for full hand strength.
 

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DocAriel

GP100
Joined
Feb 12, 2023
Messages
8
Location
California
When you do so, do it in a plastic bag. Don't ask me why.
And the SP's in general are not known for smooth actions. But if one performs the "Poor boy's trigger job" it definitely improves, because it mimics thousands of cycles without firing ammo.
'Don't ask me why' 🤣🤣 …because you'll find out immediately why you should have if you didn't…
 

silverback

Blackhawk
Joined
Aug 9, 2012
Messages
591
Location
el paso texas
Look at Mcarbo trigger spring installfor gp100 and sp101. Best most informative detailed video on what to polish and how the sp101 works.
Follow the polish points you be glad you did.
If you get the spring kit it does make the trigger better but I found keeping the OEM hammer spring maintained primer strike reliablity.

 

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