Trigger Polishing

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Feb 28, 2003
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Cajun Country, La.
Just recently I installed a Galloway trigger in my SD9. I had already installed an APEX spring kit in it about 2 years ago. That brought the trigger pull down to 5 lbs. from almost 7.5 lbs. Polishing the trigger bar, sear, and adding the new trigger brought the trigger pull down to 4.75 lbs. Not only is the trigger pull smooth as silk, it shoots a lot better, more accurate.
Next is my G21 and all of my M&P's. I didn't realize a polished trigger would work out so well. Had I known this I would have polished ALL of my gun triggers a long time ago.
 
I've polished the trigger (and associated sliding parts) on my Glocks.

No real change in weight, but much smoother and a more crisp break. Very worthwhile time spent.

I haven't gone that deep into any of my S&W automatics (5906, 4006, 4506) but perhaps I should...

I installed a factory upgrade trigger in my Sig P227. It's very nice.

I polished every part in my wife's Walther CCP - virtually no difference.

C'est la vie...
 
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There's also some videos on polishing the feed ramp into the barrel. May as well do while you're in there. When you look very closely you may see burrs and nicks that can be polished out to reduce possible jam.
 
Originally Posted by BlueOvalFitter
Just recently I installed a Galloway trigger in my SD9. I had already installed an APEX spring kit in it about 2 years ago. That brought the trigger pull down to 5 lbs. from almost 7.5 lbs. Polishing the trigger bar, sear, and adding the new trigger brought the trigger pull down to 4.75 lbs. Not only is the trigger pull smooth as silk, it shoots a lot better, more accurate.
Next is my G21 and all of my M&P's. I didn't realize a polished trigger would work out so well. Had I known this I would have polished ALL of my gun triggers a long time ago.

Does that SD9 wear a manual safety?
 
Originally Posted by Triple_Se7en
Originally Posted by BlueOvalFitter
Just recently I installed a Galloway trigger in my SD9. I had already installed an APEX spring kit in it about 2 years ago. That brought the trigger pull down to 5 lbs. from almost 7.5 lbs. Polishing the trigger bar, sear, and adding the new trigger brought the trigger pull down to 4.75 lbs. Not only is the trigger pull smooth as silk, it shoots a lot better, more accurate.
Next is my G21 and all of my M&P's. I didn't realize a polished trigger would work out so well. Had I known this I would have polished ALL of my gun triggers a long time ago.

Does that SD9 wear a manual safety?

No it doesn't.
 
Just be REAL CAREFUL

Trigger pull ( depending on specific model) is a relative arrangement between the contact angles ( and geometry), depth of contact (called length of pull in guns) surface finish ( referred to smoothness) and in some cases multiple included angles/dimensions from camming of parts.

polishing ( by definition a surface finish without removing mass) helps but make sure none of the other parameters change- it can creta a very dangerous situation.

Also, some weapons use soft metals or plating so polishing can create other issues too.

Just be careful and I recommend strongly using dychem and making a contact proof too. ( make sure there is always full engagement and no geometry change)
 
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Originally Posted by ABN_CBT_ENGR
Just be REAL CAREFUL

Trigger pull ( depending on specific model) is a relative arrangement between the contact angles ( and geometry), depth of contact (called length of pull in guns) surface finish ( referred to smoothness) and in some cases multiple included angles/dimensions from camming of parts.

polishing ( by definition a surface finish without removing mass) helps but make sure none of the other parameters change- it can creta a very dangerous situation.

Also, some weapons use soft metals or plating so polishing can create other issues too.

Just be careful and I recommend strongly using dychem and making a contact proof too. ( make sure there is always full engagement and no geometry change)

Thanks ACE.
Before l did any polishing to my SD9 trigger l watched BOO KOO videos on the subject. Everything you stated was explained in detail in some of the better videos. These are the ones l paid attention to more than the others. I also kept very detailed notes on every step of my polishing procedure.
Also, l was going to use FLITZ but instead l used TURTLE WAX heavy duty rubbing compound. I did a trial run on my Glock 5.5 lb. connector that l replaced with a ZEV 3.5 lb. connector. It come out with a mirror shine.
thumbsup2.gif
 
If you really would like to learn this, here's the short method but guaranteed to produce quality safe results.

Read up on machine design and notching ( that's the sub field) to get geometry, throw, creep, contact pattern, engagement glide and so forth.

Buy a bench block, some drill rod and brass key stock in 1/2 and 1/4 ( soft enough to file easy for learning and big enough to see critical details and nuances without significant magnification but too soft for any hard locking)

If you don't do CAD or drafting, Visio works very well- center distances and notch angles ( along with run) and the arc are the critical parts to define.

Learn the fit and geometry first then drill holes and measure the function of the notch ( copy a gun part- just oversize)

Learn big then you can do small easily.

Pretty soon you can modify any trigger on any gun ( within reason) and do it safely.
 
Originally Posted by ABN_CBT_ENGR
If you really would like to learn this, here's the short method but guaranteed to produce quality safe results.

Read up on machine design and notching ( that's the sub field) to get geometry, throw, creep, contact pattern, engagement glide and so forth.

Buy a bench block, some drill rod and brass key stock in 1/2 and 1/4 ( soft enough to file easy for learning and big enough to see critical details and nuances without significant magnification but too soft for any hard locking)

If you don't do CAD or drafting, Visio works very well- center distances and notch angles ( along with run) and the arc are the critical parts to define.

Learn the fit and geometry first then drill holes and measure the function of the notch ( copy a gun part- just oversize)

Learn big then you can do small easily.

Pretty soon you can modify any trigger on any gun ( within reason) and do it safely.

Thank you Sir. I will definitely read up on it.
 
Excellent input from A_C_E. Glad to see you're taking the time to learn about this stuff, BlueOval, rather than just breaking out the Dremel (DO NOT EVER use a Dremel on a trigger or fire control).
 
I did trigger work on my Mini-14.
Studied the group under my 10x loupe.
Saw tool marks.
Went at them very delicately with the appropriate pattern file. Finished off with a 1/4' hard Arkansas stone.
Results? Golden. Pull weight didn't seem to change much but a much cleaner, crisper break.
 
Originally Posted by bulwnkl
Excellent input from A_C_E. Glad to see you're taking the time to learn about this stuff, BlueOval, rather than just breaking out the Dremel (DO NOT EVER use a Dremel on a trigger or fire control).


Actually you can ( but don't use it freehand, no human being can hold it properly)

My "proof of concept' was a locked Dremel with a cross slide vise- the "Dremel" worked but the weak spot was those stones available simply cannot be properly trued and balanced to do that level of precision work.

We would up using Norton stones for the tool sharpener on a tapered bng shaft with 0.000 backlash. ( basically made a scaled down precision surface grinder)

The design is for small pump/hydraulic components but it will do sears

My strongest recommendation is to not attempt freehand stuff (Yeah I know there are people who can hand grind tooling almost perfectly but they are the exception, not the rule and nobody is likely to get killed from a improperly worked "hair lathe tool")

Use jigs, proper measuring tools, dychem and good optics
 
I agree that one _can_ use a power tool, but only in theory when talking about a Dremel-type. You cited good reasons why one should NEVER use a Dremel on a trigger or fire control, even clamped in a fixture. (-: Too, it's far too easy for the average joe (and many I've met who claim to be gunsmiths) to overheat a part with a dremel due to its high speed, and wreck heat treatment.* That may not be pertinent, but sometimes it is.


*This _shouldn't_ ever be an issue with trigger parts, since there should not be a call for removing that much material unless there was an egregious manufacturing error. However, I've seen people do things just this dumb.
 
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Originally Posted by bulwnkl
I agree that one _can_ use a power tool, but only in theory when talking about a Dremel-type. You cited good reasons why one should NEVER use a Dremel on a trigger or fire control, even clamped in a fixture. (-: Too, it's far too easy for the average joe (and many I've met who claim to be gunsmiths) to overheat a part with a dremel due to its high speed, and wreck heat treatment.* That may not be pertinent, but sometimes it is.


*This _shouldn't_ ever be an issue with trigger parts, since there should not be a call for removing that much material unless there was an egregious manufacturing error. However, I've seen people do things just this dumb.


I'm so glad you said that- I see you have been there too once or twice

I have to "fix" previous jobs all too much

I almost exclusively wet grind so that's not an issue on my end but on many modern guns they have a soft stamping that's been either plated or just surface hardened. People mess that up then it has all the structural strength of machining wax- those are the dangerous ones
 
Originally Posted by Triple_Se7en
You arren't carrying it in your pocket.... are you? The SD9 pics look like it's a little too large for pockets.

The SD9 is the same size as the G19/23. I think the grip is about 1/2" longer on the SD9. I can get all of my fingers on the SD9. On the G19/23my pinky is hanging out in limbo.


20190820_122440.jpg
 
Originally Posted by ABN_CBT_ENGR
Just be REAL CAREFUL

Trigger pull ( depending on specific model) is a relative arrangement between the contact angles ( and geometry), depth of contact (called length of pull in guns) surface finish ( referred to smoothness) and in some cases multiple included angles/dimensions from camming of parts.

polishing ( by definition a surface finish without removing mass) helps but make sure none of the other parameters change- it can creta a very dangerous situation.

Also, some weapons use soft metals or plating so polishing can create other issues too.

Just be careful and I recommend strongly using dychem and making a contact proof too. ( make sure there is always full engagement and no geometry change)



In the interest of correct information, "length of pull" is a rifle/shotgun term, it is the distance between the front surface of the trigger and the buttplate, something on the order of 13-16" give or take, different on different guns. It refers to the "fit" of the firearm to an individuals build. The term you're looking for is "sear engagement" the depth of the engagement surfaces.
 
Originally Posted by bchannell

In the interest of correct information, "length of pull" is a rifle/shotgun term, it is the distance between the front surface of the trigger and the buttplate, something on the order of 13-16" give or take, different on different guns. It refers to the "fit" of the firearm to an individuals build. The term you're looking for is "sear engagement" the depth of the engagement surfaces.


Yeah, in the interest of timing, that case of "lost train of thought during posting" was brought to my attention by several but not before editing expired.

In the interest of more detailed correct information "sear engagement" is the correct term for describing the overall function but is too general for actual notch actuation and function design. The surface depth of the notch has more to do with timing ( from point of actuation) and backlash with possibly initiating other functions than it does with the actual initiation. The geometry, hardness. combined angles and any arcs as well as surface contact have more to do with the actual initiation. I simply wasn't going into that much detail on a board.

The whole point was, given the potential for danger, don't do this at home just on the basis of a video that may only show one dimension of a very complex subject.

But you are correct, I used the incorrect wording.
 
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