S&W 929 Trigger Adjustments

Dirt Merchant

Dirt Merchant

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I am trying to get to the bottom of how to lighten up the trigger on a new S&W 929 and I have run into several conflicting opinions on Youtube. When I look at what Jerry Miculek has to say, he says to buy his spring kit and then grind down the strain screw to appropriate trigger pull weight until you don't get light strikes with the ammo you use. According to Jerry, 7.5 lbs is pretty good. https://www.youtube.com/watch?v=H9gn7zE5b3g
Others on Youtube say you should NEVER grind down the strain screw but rely on a complete trigger job, done by a professional (including springs), to get the desired pull weight. I generally shoot American Eagle 124g. I have Wolff springs in my older 686 with trigger pull of around 6.5 in DA which is where I would like to get to.
 
Smoothing internal surfaces, spring kits, and work in, all work together to reduce and improve trigger pull. The spring kit and grinding the screw sounds like the simplest DiY option for a non gunsmith.
 
I've never heard of grinding the strain screw... I just relieve the grips, as needed, to clear it.

I have a few guns that have had trigger work done. I've had to add at least half a turn to the screw to get them reliable since I don't buy soft primers, so I'm glad the thing wasn't ground down!
 
I agree that grinding down the relief screw is a bad idea. It's too easy to go too far and end up needing a new screw. Instead I'd just buy the spring kit and install both the rebound spring and the lighter mainspring then set the screw all the way in. If' that's still not light enough you could grind the replacement mainsprings sides down to make it thinner and reduce the pressure.

You can back out the screw as a temporary change at the range to see how much more lighter you can go. If you move it 1/8 of a turn and still get reliable ignition you could grind off quite a bit more of the reduced power mainspring.

My experience has been that the reduced power mainsprings will typically not be reliable with all primers even with the strain screw set all the way in. Now I order a replacement full power main spring and grind the sides down.
 
MuthaFunk said:
I agree that grinding down the relief screw is a bad idea. It's too easy to go too far and end up needing a new screw. Instead I'd just buy the spring kit and install both the rebound spring and the lighter mainspring then set the screw all the way in. If' that's still not light enough you could grind the replacement mainsprings sides down to make it thinner and reduce the pressure.

You can back out the screw as a temporary change at the range to see how much more lighter you can go. If you move it 1/8 of a turn and still get reliable ignition you could grind off quite a bit more of the reduced power mainspring.

My experience has been that the reduced power mainsprings will typically not be reliable with all primers even with the strain screw set all the way in. Now I order a replacement full power main spring and grind the sides down.
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I tried to find a Youtube video on grinding the sides of the main spring. How much do you usually have to grind off? I understand that trigger pulls are a personal preference but what kind of DA trigger pull weight is considered practical for competition shooting?
 
I installed an Apex DAO hammer and it is very smooth. I never measured the weight because I find it irrelevant when something is that smooth. All factory springs. Strain screw cranked as tight as I can get it for some unknown hard primers on factory re loads. Get stronger fingers and you will save a lot of money lightening trigger parts.
 
MustangFrank said:
I installed an Apex DAO hammer and it is very smooth. I never measured the weight because I find it irrelevant when something is that smooth. All factory springs. Strain screw cranked as tight as I can get it for some unknown hard primers on factory re loads. Get stronger fingers and you will save a lot of money lightening trigger parts.
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Nice! Since I am more of a tinkerer (I already polished the insides so its pretty smooth) than a shooter I will look into the Apex hammer. I ended up filing down a 8-32 bolt to get the trigger pull of 7 lbs 10oz. I will go give it a try and see what happens. Fingers (weak) crossed!
 
I installed a Wolff competition spring kit in my 686 and stoned the sears, polished the pivot pins etc etc. It's a totally different gun from factory.
 
Trinimon said:
I installed a Wolff competition spring kit in my 686 and stoned the sears, polished the pivot pins etc etc. It's a totally different gun from factory.
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That is about what I did except I didn't install the Wolff main spring. I installed the 13 lb rebound slide spring as that is what I had left over from a set. I guess what I am trying to figure out is which component has the most noticeable effect on the feeling of the firearm. I can easily change out the main spring to the Wolff competition spring or try a 12 lb rebound spring but its a 2 hour round trip to the range to find out that my changes have resulted in light strikes. I guess that is why I asked in the OP what is a goal for a trigger pull weight (Jerry says 7.5 lbs and I believe he has big strong hands/fingers). As it stands, I was able to shoot American Eagle, Winchester, Blazer and Sellier & Bellot 115g and 124g without issue today with a trigger pull weight of 7 lbs 10 oz, which is the only quantifiable data that I can come up with.
 
Trinimon said:
Do you reload? If so, you can just use some primed cases and see if the primers pop reliably?
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I don't personally reload but my shooting buddy does. I do live in an apartment in Vancouver so if you are suggesting that I make some adjustments and then shoot off a couple of rounds with only primers in them, I would have to know exactly now loud that would be inside an apartment den, in the middle of the city as I would just hate to have the Vancouver City Police knocking down my doors in full SWAT gear. If that is not what you meant, I apologise.
 
Dirt Merchant said:
I don't personally reload but my shooting buddy does. I do live in an apartment in Vancouver so if you are suggesting that I make some adjustments and then shoot off a couple of rounds with only primers in them, I would have to know exactly now loud that would be inside an apartment den, in the middle of the city as I would just hate to have the Vancouver City Police knocking down my doors in full SWAT gear. If that is not what you meant, I apologise.
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You had best do that at the range. They are pretty damn'd loud and a fire hazard to boot. I've done it a couple of times in my basement and have walked away with ringing ears each time.

M
 
Dirt Merchant said:
I don't personally reload but my shooting buddy does. I do live in an apartment in Vancouver so if you are suggesting that I make some adjustments and then shoot off a couple of rounds with only primers in them, I would have to know exactly now loud that would be inside an apartment den, in the middle of the city as I would just hate to have the Vancouver City Police knocking down my doors in full SWAT gear. If that is not what you meant, I apologise.
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Yeah, don't do that in an apartment. The loudness you can muffle but the smoke etc, not so much. Might set the fire alarms off.
 
Dirt Merchant said:
I don't personally reload but my shooting buddy does. I do live in an apartment in Vancouver so if you are suggesting that I make some adjustments and then shoot off a couple of rounds with only primers in them, I would have to know exactly now loud that would be inside an apartment den, in the middle of the city as I would just hate to have the Vancouver City Police knocking down my doors in full SWAT gear. If that is not what you meant, I apologise.
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I've done a bunch of trigger work and customizations on my 929's. For testing primers, I lined a pail with old mouse pads, and it muffled the sound very well. It's about the same as a paperback book falling on the floor.

I run a 929 in IPSC revolver division sometimes. Currently it's setup with an Apex hammer, Wolf reduced power main spring (with a custom bend to it), fully polished internals, 11lb rebound spring, Dawson front fiber optic sight, VZ G10 grips, and Hogue extended length cylinder release. I can run as light as 5lb's using Federal primers, but I keep it at 6lbs just in case. Yep, I like to tinker .... lol
 
When I replaced the hammer spring in my GP100 I was forced to switch to Federal primers. Slowly switching all my revolver reloads to Fed. Had a s..t load of 38s reloaded with CCI primers. Work ok single action, not so much in double action. The Federals go bang every time in either mode.

M
 
VanMan said:
I've done a bunch of trigger work and customizations on my 929's. For testing primers, I lined a pail with old mouse pads, and it muffled the sound very well. It's about the same as a paperback book falling on the floor.

I run a 929 in IPSC revolver division sometimes. Currently it's setup with an Apex hammer, Wolf reduced power main spring (with a custom bend to it), fully polished internals, 11lb rebound spring, Dawson front fiber optic sight, VZ G10 grips, and Hogue extended length cylinder release. I can run as light as 5lb's using Federal primers, but I keep it at 6lbs just in case. Yep, I like to tinker .... lol
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OK... that's pretty cool! Which Apex hammer do you use and where did you get it? I am using the Wilson Reduced spring set but the rebound spring only goes down to a 12 lb. Other than your polishing job and I assume some stoning on the sear, did you use the Power Custom Stoning Fixture to get such a light trigger pull? Would you say there is more of a noticeable improvement with the Apex hammer or from stoning the sear? I am mostly satisfied with the function of my 929 but I only did a basic stoning (21 steps on the Power Custom Fixture) but I like to tinker so, I would rather try adjusting the Stoning Fixture, since I have access to it, instead of buying a new hammer.
 
Dirt Merchant said:
OK... that's pretty cool! Which Apex hammer do you use and where did you get it? I am using the Wilson Reduced spring set but the rebound spring only goes down to a 12 lb. Other than your polishing job and I assume some stoning on the sear, did you use the Power Custom Stoning Fixture to get such a light trigger pull? Would you say there is more of a noticeable improvement with the Apex hammer or from stoning the sear? I am mostly satisfied with the function of my 929 but I only did a basic stoning (21 steps on the Power Custom Fixture) but I like to tinker so, I would rather try adjusting the Stoning Fixture, since I have access to it, instead of buying a new hammer.
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I got the Apex Hammer from Brownells h ttps://www.brownells.com/handgun-parts/trigger-group-parts/hammer-parts/hammers/evolution-iv-n-frame-hammer-prod83621.aspx
Before I did that, I just gave the sear a light run over with my finest stone, and then polished it with Autosol. I also polished the nose of the trigger that contacts the sear in DA mode.

The Apex hammer needed a little fitting, but lets me run my trigger pull ~ 1lb lighter. I decided to buy it, so I could return my revolver to a "mostly" stock configuration later. And it's nice to have a backup in case I mess things up lol. All the stoning and polishing, really just gave me a very smooth double action trigger pull (I leave the SA contact surfaces alone). A big difference will be in giving that rebound bar a good stoning & polishing. Also re-contouring the top part of the rebound bar that resets the hammer. This let me drop down to an 11lb Wolf rebound spring that still resets the trigger quickly and reliably.

A big source of the trigger pull weight reduction also came from putting a custom bend on the Wolf reduced power main spring. That gives me a range of 8lbs with the strain screw turned in all the way, to 4.5lbs with the strain screw backed out 2 turns. I found that backing out the strain screw too far, gave the trigger a mushy/sproingy feel, so I prefer to have it turned in most of the way. Putting an "S" bend into the main spring gave it lightened the trigger pull, but still left a nice firm pull and reset.

Get the Hogue extended cylinder release. I find that really great as I do a weak hand reload, and I don't have to change my strong hand grip at all to release the cylinder. I'll probably chamfer the cylinders to ease reloading, but I'll have to send it out to get that done. The chamfer set I have works great on stainless steel cylinders, but the titanium ones are too hard.

Here's my 929's. I always like to have two of something if I'm going to compete with it lol
IMG_5240.jpg
 

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