Ar trigger polishing.

[uncle money bags]

Explanation to follow...

 

[uncle money bags]

The picture above is the top center section of a VW type 4 race engine. This is the piece that broke away when a piston rod decided to let go and try to achieve low Earth orbit right after turn 2 at Hallett race track. It was the first race engine I built myself, without a clear understanding; tempered by experience and wisdom, of how the the system worked as a whole. I built this engine, and raced it for a total of about 6 laps. I wanted to do it myself, for budget reasons and because of a desire to "do it myself". What I discovered was the meaning behind; " The best way to make a small fortune in racing, is to start with a large fortune".
I have kept this part for 18 years, in a prominent place, to remind me of the dangers of not understanding what I am doing, as well as, seek the help of professionals when in doubt.

When I used to polish triggers for my AR FCGs I first made sure I understood the engineering involved. This includes the metallurgy, polishing, and how seemingly minute changes in one area can drastically change the system as a whole.
This is how I did the trigger sear surface mentioned by the OP. I am posting this as an example, not as a guide.

I started with a sheet of 1200 grit wet/dry paper, using a glass block as a base.
Using a small amount of thin oil, I coated the surface of the paper.
Under magnification, I ensured the sear surface was flush against the paper and with light pressure traced a single figure 8.
Wipe the oil off the sear and inspect under the same magnification. I am trying to produce an even surface without broaching the hardened surface.
In order to not break the hardened surface I will not repeat the figure 8 more than 3 times, and honestly that is twice more than I prefer.
Satisfied that I have a surface I can polish without damage, I move on to a small, hard felt wheel and a small amount of very fine polish. Something more abrasive than jewelers rouge, but less so than tripoli.
Using a high end dremel type hand piece and slow speed i polished the sear surface. The direction of the wheel in relation to the sear is important. You do not want the polishing to round over the leading edge of the sear engagement, so the wheel should "pull" over not push into that edge.
A few seconds is all it takes. Any more than that can damage the surface hardening. It may not look like a mirror, and in fact that isnt the goal. The goal is a more consistent, less gritty pull.

Having said all of that, I no longer do this type of modification. Not because this is a bad way to fix a crappy feeling GI trigger, but because there are alternatives that are significantly better than you can achieve doing this.
Geissele gets my money. There is no finer combat trigger made, and every firearm I have that can take one, gets one.

 

[Jwryan84]

So we are back to the SSA-E. Holler at me if you want to feel one in all its perfection. I'm in NW OKC and like I said, by the time you get your stamp you will see sales.

Ive had an SSA and wasn't near impressed with the pull. I have ARs witht the JP yellow springs and have to watch what goes in them as hard primered foreign ammo is about 80/20

 

[gfercaks33]

As a whole I was going to attempt something like UMB was saying go real slow and learn how to do it, I live in a constant state of trying to learn new things.

UMB- that is a good story of the I have a few of those parts my self in the garage and spent the better part of 3 years undoing stuff I cut corners with on my car.

Jwryan- I may take you up sometime to check it out, I have never pulled the trigger of a geissele but the cost has put me off of it. Also this one will probably be another longer project as a part here and there.


I'm not trying to go to town grinding, cutting and buffing I was hoping to make a few passes to clean it up.

 

[Glocktogo]

What UMB is alluding to is just how microscopically thin the hardening is. The problem is that the trigger will feel great, right up to the point it lets go. When it lets go, it's likely to send more than one round per trigger pull downrange. If your disconnector isn't right, you could have an out of battery kB. That can get ugly quick and there are a lot of AR parts on the market that aren't to spec. I had to replace a disconnector in one of my cousin's AR kits last year because it was crap.

All we're saying is that the surface flaws on some maker's engagement surfaces are deeper than the hardening, so proceed with caution!

 

[Jwryan84]

As a whole I was going to attempt something like UMB was saying go real slow and learn how to do it, I live in a constant state of trying to learn new things.

UMB- that is a good story of the I have a few of those parts my self in the garage and spent the better part of 3 years undoing stuff I cut corners with on my car.

Jwryan- I may take you up sometime to check it out, I have never pulled the trigger of a geissele but the cost has put me off of it. Also this one will probably be another longer project as a part here and there.


I'm not trying to go to town grinding, cutting and buffing I was hoping to make a few passes to clean it up.

Anytime I live on NW side, Morgan and Memorial. I have at least 1 with JP Springs, an SSA-E, and an SD3G.

Just know it can be pretty dangerous if you get something out of square. Don't want something you trust your life to, to not work

 

[dennishoddy]

What UMB is alluding to is just how microscopically thin the hardening is. The problem is that the trigger will feel great, right up to the point it lets go. When it lets go, it's likely to send more than one round per trigger pull downrange. If your disconnector isn't right, you could have an out of battery kB. That can get ugly quick and there are a lot of AR parts on the market that aren't to spec. I had to replace a disconnector in one of my cousin's AR kits last year because it was crap.

All we're saying is that the surface flaws on some maker's engagement surfaces are deeper than the hardening, so proceed with caution!

Yes. When I say I like to play with triggers and use the JP's that have to be fit and tuned, its because I know what may happen if its not right. After assembling the first and looking at how important the entire system has to operate, it really opens up ones eyes about how all of the components have to function correctly.
The disconnector GCG talked about is something you certainly don't want out of time. When using JP components, they will warranty the disconnector one time if you screw it up with tuning, no fault.

Here is a prime example of why trigger work has to be approached with caution.

I installed a Majestic arms trigger kit in my Ruger Mark III Hunter Steel Challenge gun. Reduced the trigger down to 3lbs which is optimal for that type of comp. It had too much reset though.(in my opinion) I got swamped with work and took it to a very reputable local smith to see if he could help with that. Got it back, and it worked great!
Next match, second stage, it wouldn't reset. Ran the safety on and off, and it started working. Went back and it didn't reset again, so I told the RO I was done, dropped the mag, turned to put it on the table, and the pistol fired on its own. 4 witnesses including the RO said my finger was out of the trigger guard.

Took it back to the smith, and three days later got it back with a no charge tag attached. Works great now, but that is just an example of how critical trigger work can be.
Sorry about the long winded story.

 

[shooterdave]

GFer, remember that aftermarket triggers reach a point of reliability by geometry more so than polishing. Someone mentioned a few posts ago that the surfaces of the sear and engagement are very hard, and VERY THIN. That is, the hardening does not go thru the entire part. It would be too brittle. Just the surface is hardened. If you manage to get underneath the hardened portion, the piece is useless. More importantly, you are playing with fire by doing anything to the hammer and sear. Everything short of wiping them down and polishing with a non abrasive compound runs the risk of creating an unsafe firearm. Remember that you are responsible for the bullet until it stops! Take almost everyone's advice and buy an aftermarket trigger. They have done the research and design to manufacture a product that is safe and meets your criteria. Good Luck!

 

[gfercaks33]

I think where I am in life I don't want to spend money on a trigger that I can build another couple lowers for, I am now broadening my search what about doing something like a spikes battle trigger or a bcm gunfighter, those are like $60 and they have done the polishing and coated them with Teflon or something like that.


I do understand the safety concerns with it, on my current rifle I have the set screw, jp springs and speed hammer, before I made the speed hammer I had an issue of it failing to feed I packed it up and went home. Another thing I had was I forgot to loctite the set screw and it moved causing the trigger to not reset, after 2-3 shots and I realized it was not a fluke I packed it up and shot the 10/22 the rest of the day. I really do appreciate the concern and I have been taken notes on everything.

 

[NikatKimber]

I would recommend the ALG QMS. It's not coated, and from the discussions on here, is a little better than the coated triggers ALG does. Do not know how they compare to other makers though.

I have the QMS along with the JP springs, and a grip screw trigger adjuster. Makes for a fine ~$75 trigger.