M*CARBO Brotherhood

Trigger Creep Elimination

The radius I placed on the rear of the sear was about only enough to reduce the pressure on the mating surfaces.
I do not have the tools to measure what I did other than to reduce the amount of upward pressure that would raise the hammer ever so slightly right before the square edge of the sear would disengage. I just used a small file and went through the polishing protocal of paper and Flitz


You can see my results.

Alot of my trigger pull reduction came from the work I did on the mating surfaces as described in those other posts.
I look back on those pictures (from 10 days age) and see how far, not only my knowledge of the S2K but how to edit adding graphics to pictures to clarify descriptions has come. This has happened just because of the shear embarrassment of pen drawing vs. computer editing. This has come about because of the real nice presentations of others.

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Now that I look back at the hammer in triggerhappy’s thread I see the big “bite” out of the edge of the hammer must have been OEM. OMG!!! Why?

Oh my!

Actually, I’m pretty OK with the weight of the trigger pull, it’s the creep to engage that I want to shorten. When I get some time I’m going to install the new trigger bar and I’ll take a look at doing some more polishing. I’m OK with the way mine’s running right now and I just bought a new M&P 9 2.0 that’s being delivered Friday and I’ve got an Apex trigger I’m putting in that. Once I get that one done and tuned up I’ll get back to playing with Sub.

sounds like lots of fun.
GL

Okay, I can’t figure out how to do a general post so I am repying to you.


This is basically the stuff you will need. There are no special sizes to anything here, use whatever it takes for your particular drill press. I. using the $60.00 dollar job from harbour freight.
You are only removing about .030", and will shorten the sear contact surface.

When finished, this thing should look something like this.

1: Base. It needs to be very flat and parallel and whatever size it needs to be to clamp to your particular drill press table.

2: Slider. It needs to be very flat and parallel, and needs sit a shade higher than the side rails so the clamps will press down on it when snugged.

3: Rails. The surfaces that contact the bass and slider need to be flat and square(no bow) so that the slider will slide staight and even.


Attach the first rail like so. I forgot to mention that clearance hole in rails for the screws need to be drilled first.
Now with the slider between, apply gentle pressure and attach the other rail. The slider should slide straight with no sideways wiggle.
Now screw in the clamps but just barely snug them so the slider slides, but does’t lift up.
Clamp the assembly to your drill press table so the center of the drill press spindle is as close to center of the slider as possible. From here on out, you can’t remove the assembly or move the drill press table, so make sure you have enough verticle spindle movement to finish the job.
Now chuck your 3/8" stone in and use a good square to check for squareness of the stone and the slider with the clamps gently snugged. This is the tricky part. If you don’t have a table angle adjustment feature on you drill press, you’ll have to shim under the base on one end or the other to square the slider to the stone.

I used this type of razor blade because most folks don’t have a precision square. These blades are surprisingly square at the edges indicated with sq

Now sink a .120" hole 1/8" from the edge of the slider. Lightly snug the clamps down first. Don’t go all the way through the slider. a half inch is good. You are going to press a .125" dowell in the hole and you don’t want it to go into base and prevent the slider from sliding. I used a .120 drill because the dowell needs to be a fairly tight fit.
Grind or stone a slight taper on the end of the .125" dowell that is going into the slider, chuck the other end into drill chuck and gently press the pin into the slider. Don’t try to raise the spindle until you loosen the chuck or you will make a mess.

Now put your hammer on the dowell and position it the area to be ground is aimed an the center of the stone. With a piece of notebook paper against the stone, gently slide the slider and hammer up to the stone so thet there is a slight drag on the paper and then lightly snug the clamps. Place whatever round thing you chose(I used one of those lowes drill depth rings) but anything round with a hole in the center will do. Screw the round thing in while gently holding against the rear of the slider.
Now you are ready to grind.

rotate the hammer away from the stone and remove it from the dowell. Use your calipers to get a starting measurement. From the edge of the hole to the surface to be ground will be .187" to .188". Sorry about the crappy pic. Subtract .030" from .187" and you have .157". This is where mine ended up. You can take more or less, it’s up to you. I have only a few thousanths creep and I was fine with that. I figured any less than that and the sear would be too close to the edge creating a dangerous condition. I slapped mine around a few times and there was no problem.
Anyway, put the hammer back on the dowell and fire up the spindle to as close to 1000rpm as you can get.
11|666x500

Rotate the hammer at a slow but steady rate(make sure every time you advance the hammer that the clamps are snugged down.
After rotating back and forth until you hear no more grinding, release clamps and add use the next size feeler gage(I forget to mention those too. You will need their thicknesses to increase by only .001" at a time.). Remove the hammer frequntly to check the hole to edge distance and it will allow the hammer to cool a little. When the distance gets to about .163" or so, lower the stone so that rest of the cuts will be on a fresh, straight section of the stone.

For those of you who, like Kona and Trigger happy disassemble their subs while they sleep, a good Idea would be to keep testing the amount of creep by installing and grinding and installing again until happiness is achieved.
When the job is done I recommend Trigger happy’s polish job.
Okay, I’m going to hit the reply button now. Hope it works!

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@GinNC Thanks for the great tutorial with pictures. Some of us need pictures as well as word. :roll_eyes:

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I triple down with godalmighty
:heart_eyes::heart_eyes::heart_eyes:
Thanks for all the Work !!!
Believe me I know how much time it takes to do this kind of work to document your efforts
!!!
I am pretty ignorant !!!If If it don’t have pictures I can’t read it. :rofl:

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I am a wood worker and have an oscilating sander that has rigid rubber drums and fine sand paper. it will take longer but can stack bloch of 1/2 cabinet plywood up and remove or add to change height I see the jig idea now and will be able to do that on that machine. By the way I went to the range today with what i did to mine.
I settled on a sear that gave me 2lb 15oz with LAX .40 180gr reloads.

25yds Factory sights on black target with red dot stickem ups inside.

my last 2 targets

There were 4 shooters there that have S2k’s they never heard of MCARBO before to day. they are coming in after trying mine. I took Trigger gauge with me and showed them the difference 6lb 6oz factory trigger and oooops jaws dropped. 2 of those shooters do long distance out to 1000yds competitions

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Looks good. The lowest pull I get is 4lbs 2oz.

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Gary, how does your gun shoot now ?

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if you want it just a little bit lighter then just polish it a little. if you want to go to total “GUN CONTROL” then as quiet the gun can get (smallest amount of vibration) then the louder the response (easier get good results). I do not shoot in competition. My daddy told me to do as I could.
So I try.

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I have 4 sears. I can change the trigger pull by replacing the sears.

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Mine functions really good. Like I said, it shows about 4lbs2oz. pull and has nice crisp snap almost immediately beyond the wall with maybe .003” to .005” max creep. I still need to do the mcarbo trigger bar fix to cure the reset issue when dry firing after cleaning. It’s not an issue with live fire, but it’s still a fly in the oatmeal.

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Oatmeal can get messy

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some more bump up work.
Good stuff inthis thread also

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Well written. Great insight

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