Polishing AR trigger & hammer with car polish compound

[Charlie Martinez]

Just watched a video on You Tube where parts of the trigger and hammer are coated with car polish and worked a few dozen times resulting in a much improved trigger pull. It seems easy enough and improves trigger without having to replace milspec springs or buying (expensive) an aftermarket trigger replacement.

Has anyone tried this? If so what were your results?

 

[HKGuns]

I don't mess around with triggers. You have to know what you are doing and it doesn't take much to screw something up or make it unsafe.

If you don't like your trigger, buy one that meets your definition of good.

I keep my Colts stock, all others get G SSA-E.

 

[mcb]

I have never had much luck making the standard mil-style semi-auto fire control that much better. I personally prefer a two-stage trigger and have install aftermarket ones in most of my ARs. If I was going to stay with a mil-style fire control I would upgrade to an Geissele ACT or similar trigger (the ACT is only $83). Same basic fire control but made from better materials, machined to tighter tolerances, and better finishes. The basic mil-style trigger is not worth much IMHO.

 

[trackskippy]

Ive been playing with one of my AR's with a standard trigger that has a little "crunch" in it, just trying to clean it up a bit. The trigger as it came wasn't bad, just a little crunchy/gritty.

At first, I tried putting some Mothers on the sear and just "snapping" the trigger, over and over while watching TV, and that did clean things up a good bit.

More recently, I took the trigger out and used a Dremel with a felt tip and some polishing compound, and went over it a bit, and actually polished the surfaces. That has made a big difference and the crunch is gone. It still has that initial short, pressure type take up to it, but the break is clean, smooth, and unexpected. I took it out and put a couple of mags through it when I was done and didn't have any problems and everything ran as you'd expect.

I don't mind the factory weight triggers and don't have a problem shooting well with them. What can be annoying is that "crunch", which all seem to have a little bit of, and some have it more than others. I'm not stoning anything, or doing anything but just carefully polishing and cleaning up the surfaces.

After hearing all sorts of praise about them, I did try one of the Gessele ACT triggers in my one Armalite, and I wasn't all that impressed with it. It was a tad better than what was in the gun, but it still had some crunch to it, and really doesn't feel any different than a standard AR trigger. I wouldn't spend the money on it. If you're going to drop around a hundred, might as well drop two and get something that's better. Assuming it really is. I often think a lot of the whole trigger thing is good marketing and in peoples heads too.

 

[d2wing]

You can buy trigger sets that are already polished. Midway or Brownells.

 

[N555]

I have never had much luck making the standard mil-style semi-auto fire control that much better. I personally prefer a two-stage trigger and have install aftermarket ones in most of my ARs. If I was going to stay with a mil-style fire control I would upgrade to an Geissele ACT or similar trigger (the ACT is only $83). Same basic fire control but made from better materials, machined to tighter tolerances, and better finishes. The basic mil-style trigger is not worth much IMHO.

The cheapest AR trigger groups I could find is what I used to learn how to do trigger jobs. Now I can make an AR trigger break anywhere from slightly improved, lawyer approved to dangerously light.
It's not that difficult.

 

[N555]

Just watched a video on You Tube where parts of the trigger and hammer are coated with car polish and worked a few dozen times resulting in a much improved trigger pull. It seems easy enough and improves trigger without having to replace milspec springs or buying (expensive) an aftermarket trigger replacement.

Has anyone tried this? If so what were your results?

It will take more than that.
Doing the car polish trick won eliminate any of the creep. It might slightly reduce the pull force. I would be shocked if it reduced the break force by even a half pound.

 

[doubleh]

I don't see a way to mess up a trigger with a polish that is made for paint. It's not aggressive enough to do so. I have no use for the mil spec AR trigger because it is too heavy to suit me. I use a LaRue trigger in my one lonely AR.. No grit or scratch, nice pull weight, and the price is right.

I do not mess with mil spec AR triggers to make them lighter. Case hardening is a very thin layer and if you remove that it will wear quickly. I suppose some mil spec triggers may be made from hardened steel now but they were not when I was interested in a lighter trigger. That is a subject I have paid no attention to in years.

 

[Hookeye]

To avoid any worry, just buy a LaRue MBTS.

Just checked, they aint on sale anymore. Bummer.

Had no problems w GI triggers and JP springs. But I shot domestic commercial ammo.

 

[jmorris]

I take mil-spec trigger groups and stone them quite often. I use JP springs and add a set screw under the grip screw (allows me to adjust sear engagement).

 

[someguy2800]

Every AR I build gets the set screw sear engagement mod. If its one I care about getting a nice trigger pull on I bend the trigger return spring, clip half of one leg off the hammer spring, and polish the sear surfaces with 1000 grit paper. I doubt most car polish has a sufficiently hard abrasive to polish case hardened steel, but I guess I can't say I've tried. You would be amazed at how good you can make a mil spec trigger in about 45 minutes if you know what you are doing. Better than most of the sub $200 drop in triggers. If you understand how much sear engagement is needed and how the reset lever works it is 100% safe.

 

[InTheSwamp]

I don't mess around with triggers. You have to know what you are doing and it doesn't take much to screw something up or make it unsafe.

If you don't like your trigger, buy one that meets your definition of good.

I keep my Colts stock, all others get G SSA-E.

Yep! A little change in geometry and it becomes a "fun switch" - Buy a better trigger.

 

[N555]

I don't see a way to mess up a trigger with a polish that is made for paint. It's not aggressive enough to do so. I have no use for the mil spec AR trigger because it is too heavy to suit me. I use a LaRue trigger in my one lonely AR.. No grit or scratch, nice pull weight, and the price is right.

I do not mess with mil spec AR triggers to make them lighter. Case hardening is a very thin layer and if you remove that it will wear quickly. I suppose some mil spec triggers may be made from hardened steel now but they were not when I was interested in a lighter trigger. That is a subject I have paid no attention to in years.

Modern AR stuff does not appeare to be case hardened.

 

[mcb]

Modern AR stuff does not appeare to be case hardened.

That is hard to believe. If they are made from cast blanks the way a mil-spec hammer/trigger is the case hardening is what gives the parts its strength since the cast alloy itself has such a low carbon content it can't really be heat treated. Look the face of a hammer if its case hardened it will be smooth (though the finish will likely be worn shiny) if its not case hardened it will develop a dent in the strike face from repeatedly striking the firing pin.

The except would be Geissele (an a few others) that make their fire control parts from tool steel (often S7).

 

[doubleh]

Modern AR stuff does not appeare to be case hardened.

How are you to know unless it is stated to be? I suppose you could take a diamond hone to the rear of the trigger and remove enough metal to see if a file would cut it but that would be rather drastic. Case hardening does little for strength. It is a cheap process to prevent surface wear. Don't believe me case harder a piece of 1018 (non heat treatable) and then take a hammer to it on an anvil or other hard surface. It is still mallable.

 

[mcb]

How are you to know unless it is stated to be? I suppose you could take a diamond hone to the rear of the trigger and remove enough metal to see if a file would cut it but that would be rather drastic. Case hardening does little for strength. It is a cheap process to prevent surface wear. Don't believe me case harder a piece of 1018 (non heat treatable) and then take a hammer to it on an anvil or other hard surface. It is still mallable.

Case hardening makes it dramatically stronger assuming the case is thick enough. It has it's largest effect on bending loads and less so on compression/tension. It's also makes it much more wear/abrasive resistant than the same allot without the case. Finally it makes for a very tough part, your have the very hard outside surface for strength and abrasive resistant but the softer core to make it tough to impact.

ETA: AISI 8620 a common alloy used in AR trigger and hammer castings. The raw casting after normalization will have a yield strength of ~50,000 psi. After carburization (case hardening) the case hardened alloy will have a yield strength basically three times that at ~150,000 psi.

 

[crestoncowboy]

I don't mess around with triggers. You have to know what you are doing and it doesn't take much to screw something up or make it unsafe.

If you don't like your trigger, buy one that meets your definition of good.

I keep my Colts stock, all others get G SSA-E.

I don't see a way to mess up a trigger with a polish that is made for paint. It's not aggressive enough to do so. I have no use for the mil spec AR trigger because it is too heavy to suit me. I use a LaRue trigger in my one lonely AR.. No grit or scratch, nice pull weight, and the price is right.

I do not mess with mil spec AR triggers to make them lighter. Case hardening is a very thin layer and if you remove that it will wear quickly. I suppose some mil spec triggers may be made from hardened steel now but they were not when I was interested in a lighter trigger. That is a subject I have paid no attention to in years.

Exactly. We dump it on a brand new 100k dollar car and mash a DA all over it. Then we dump a little less aggressive paste and do it again....sometimes a few times to get the clear perfect to do a ceramic coat. Lol.

There is absolutely no way you could hurt the metal trigger with it. Usually that's reserved for a file or a dremel.

Old guys used to be all for toothpaste in a revolver to mate and smooth all the parts.

Personally I just buy a better AR trigger. Some of the cheaper options like psa are actually not terrible these days. Hell of a lot better than a polished Mil trigger at least.

 

[dfariswheel]

People have always done things like putting toothpaste, valve grinding compound, metal polish, etc in firearms actions with the idea it'll make it smoother.

It may, but it also puts many years of wear on the parts and reduces the life of the gun.
The problem is, an abrasive removes metal EVERYWHERE, not just on the surfaces you want it to work on.
Some surfaces have to be sharply defined and an abrasive rounds those off with everything else.

If this really worked and didn't cause harm, every custom gunsmith would be dumping abrasives in guns and offering it as a service.
They don't and that's for a reason.
Trigger assemblies can be improved by knowledgeable smoothing of key areas, and no where else.

 

[HKGuns]

If polish is so harmless, then just use grease or oil. Problem solved. Nobody ever ruined a trigger with oil or grease.

 

[someguy2800]

Yep! A little change in geometry and it becomes a "fun switch" - Buy a better trigger.

It does not work like that at all. Like not at all. Maybe if you are using an angle grinder. The only way you can get an AR trigger to inadvertently go auto is if you grind on the sear surface so far that it no longer catches the sear when it comes off the reset hook. Polishing with compound or a fine stone or fine sandpaper is not going to make that happen.

 

[N555]

Yep! A little change in geometry and it becomes a "fun switch" - Buy a better trigger.

Normally you get a dead trigger and that's only going to happen when you go way to far and there's no reason to mess jhhhhjj the seer.

 

[N555]

How are you to know unless it is stated to be? I suppose you could take a diamond hone to the rear of the trigger and remove enough metal to see if a file would cut it but that would be rather drastic. Case hardening does little for strength. It is a cheap process to prevent surface wear. Don't believe me case harder a piece of 1018 (non heat treatable) and then take a hammer to it on an anvil or other hard surface. It is still mallable.

Spark check

 

[InTheSwamp]

It does not work like that at all. Like not at all.

Here's a guy asking about experinces after watching one YT video in such matters. It would be reasonable to think he's willing to go the distance. I see two acceptable answers to his question:

1- Share your experience, as he asked.
2 - Warn him about the worst possible outcome - it could happen to him! He just watched a video.

I chose #2.

 

[someguy2800]

The cheapest AR trigger groups I could find is what I used to learn how to do trigger jobs. Now I can make an AR trigger break anywhere from slightly improved, lawyer approved to dangerously light.
It's not that difficult.

How nice of ole Gene to put that threaded hole right where we needed it! Probably the easiest trigger there is to work on.

 

[N555]

That is hard to believe. If they are made from cast blanks the way a mil-spec hammer/trigger is the case hardening is what gives the parts its strength since the cast alloy itself has such a low carbon content it can't really be heat treated. Look the face of a hammer if its case hardened it will be smooth (though the finish will likely be worn shiny) if its not case hardened it will develop a dent in the strike face from repeatedly striking the firing pin.

The except would be Geissele (an a few others) that make their fire control parts from tool steel (often S7).

It's $20 worth of parts