Working on an SP101 Trigger


June 16, 2010, 11:46 AM
... I'm thinking about putting in a lighter trigger spring, possibly a wolf, in my SP 101. If anyone has doen this, is it easy to do? Still afford reliable ignition?

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June 16, 2010, 01:37 PM
I did it it's not hard. I bought the spring pac from midway I think the factory sping is 12lbs I put the 9lb in with no ignition problems.

June 16, 2010, 02:24 PM
Pete, How much of a differance did it make in the DA/SA pull?

June 16, 2010, 04:12 PM
The trigger spring will not affect ignition reliability, lightening the hammer spring will. However if the trigger spring is lightened too much it will slow down the trigger reset in DA. In other words, your finger will have to wait for the trigger to catch up in fast DA firing. Lightening just the trigger spring will not have very much effect on the trigger pull weight. If you want to significantly reduce the trigger pull weight some work will need to be done on the hammer/sear engagement and deburring and smoothing the internal surfaces of the frame and trigger parts. Lightening the hammer spring a little will help the trigger pull but ignition reliability needs to be kept.

June 16, 2010, 09:42 PM
The cheapest trigger job is dry-fire. I leave my springs alone. If there are "hitches in the gitalong" of the trigger pull, those need to be smoothed by someone who is comfortable working with stones on the internal parts. The best way to avoid those hitches is to cherry-pick the SP101. (I stoned some hitches in my first GP100. Very carefully, I might add.)

I like the primer to get a GOOD whack, so I leave the mainspring alone.

I want the trigger to return FAST, so I leave the trigger return spring alone.

I am not a big, athletic guy, but a weakling with a chronic injuries affecting one of my hands. I leave my springs alone.

Once upon a time, I did try a lighter mainspring in a GP100, and had some failures to fire, so the factory spring went back in. I left the lighter trigger return spring in place, but later, after acquiring another GP100, learned how this slowed my follow-up shots just a bit. This was with the heaviest of the several trigger return springs in the kit.

Chuck Perry
June 16, 2010, 10:39 PM
I dry fire the living crap out of my SP. It really has made a difference. The pull is still heavy, but smooth. I can also stage the trigger really well, something I don't think I'd be able to do if I lightened the springs up. I find that I like the ability to stage it for long range accurate fire more than a lighter, steady pull through.

June 16, 2010, 10:46 PM
I think that lots of dry firing has a much greater effect on your finger's muscles than it does on the action of the gun. The gun may get a tiny bit smoother but your hand is going to get much stronger.

June 17, 2010, 09:36 AM
Thanks for the responses. I have dry fired it a lot. As far as "cherry picking" a revolver, I paid $300 for it used in very good condition, so I cant complain. What I DONT want is reliablity issues as this is my carry gun some of the time.

I do have big hands and a good grip, I guess I just like the feel of a slightly lighter pull.

June 17, 2010, 12:31 PM
As noted above the hammer spring will have a greater effect on trigger pull than the trigger return. The stock springs per Wolff are rated at 10 lbs (trigger return) and 14 lbs (mainspring). Wolff offers an 8 lb trigger return and 9, 10, 11, 12 lb mainsprings. My stock SP measured 14 lbs DA and about 4.5 SA. I had Teddy Jacobson tune the gun and make it DAO and it came back with a 9 lb DA with no misfires. Out of curiousity I put in a Wolff 9 lb mainspring and the DAO went to about 8.4 lbs with no misfires. This does increase lock time , though. Often, to use the lighter trigger return spring requires some cleanup of the related parts in the trigger guard and it does slow trigger return somewhat. Whether a spring combination works in a given gun depends upon the tolerances, some do and some don't and whether the parts have been polished and smoothed inside. Also, sometimes misfires occur due to inadequate firing pin protrusion, This can be remedied readily. Over at a former gunsmith offers a guide on tuning these guns, however, he is out currently but will print some up in the Fall.

June 17, 2010, 12:31 PM
I have done a few with the Wolff springs Peak and the process is very simple.

While you have it apart polish up any areas where you see metal on metal rubbing with some 800 grit.

The new springs make for a great trigger.

June 19, 2010, 02:35 AM
I'm sorry it was the hammer spring and lighting it by a couple of pounds makes a very big differance. wolf sell a variety pack with three differnt springs so you adjustit to your liking.


June 19, 2010, 01:10 PM
Drail, don't say that too loudly. ;)

Stronger hands is the ultimate goal. :)

Of course, working the mechanism, with live or dry fire, does wear down the high spots.

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