AR Trigger Job

[kev74]

After putting the lower together on my NYGF AR build, I was left a little disappointed. I started with regular plain old DPMS lower parts kit trigger and hammer.

The first thing I did was to massage the hammer and trigger by hand with some stones to try and remove the worst of the rough edges. That made it better, but not good.

The trigger pull started with a long, gritty creepy pull before it seemed to build and then break. Looking at the trigger and hammer engagement surfaces, it seemed excessive - like the trigger was taking too big of a bite into the hammer hook. There was a lot of real estate on the hammer that the trigger had to pull over before it would break. I put some Sharpie on the hammer hook and pulled the trigger a few times to get a good idea of how much material had to come off. For what its worth, Sharpie ink makes a nice trigger lube. Who knew?!?

Now that I knew what had to come off, I had to figure a way to carefully get it off (that's what she said). A while back I made a jig to similarly re-contour the hammer on a Ruger 10/22. I dug it out and cleaned it up and was happy to find out the hammer pin on a 10/22 is the same as an AR. Woo-hoo! I can use the same jig!!

The jig I made is only a block of aluminum that I can clamp into my mill with a pin that is parallel to the rotation of the spindle. With the hammer on the pin, I can rotate the hammer against a stone in the mill and reduce the depth of the hook on the hammer in a careful, controlled way.

It worked!! I took about .0010 inch off the hook and it took about 2/3 of the creep out of the trigger pull. I think I can get it better, but I'm a little scared to take off too much. I want to figure out a better way to measure the engagement between the hammer and trigger. So far, I'm pleased. Sorry for the crappy pics.

 

[Acer-m14]

take more off take more off .. come on go full retarded .. I mean FULL AUTO hehehee LOL ..

 

[zzrguy]

I have a mill spec trigger on mine it felt like total crap and really made the gun shoot like shit the best group I got with this trigger is 2in at 50yd and 4 to 6ins at 100yds. I bought the Joe Bob trigger fix and it dropped the pull to about 4.5 and no creep for 25 buck it was worth every cent and will be going in my NYGF 6.5 Grendel build I'm doing now. I haven't stoned my AR triggers but will try and see if I can get the puke down to 3.5 that seem to be the lowest it would be safe to go to.

 

[Calculon]

I have a mill spec trigger on mine it felt like total crap and really made the gun shoot like shit the best group I got with this trigger is 2in at 50yd and 4 to 6ins at 100yds. I bought the Joe Bob trigger fix and it dropped the pull to about 4.5 and no creep for 25 buck it was worth every cent and will be going in my NYGF 6.5 Grendel build I'm doing now. I haven't stoned my AR triggers but will try and see if I can get the puke down to 3.5 that seem to be the lowest it would be safe to go to.

Joebob fix? The Grip Screw Trigger Adjuster?

 

[Sixbennetts]

 

[kev74]

Update...

I took it to the range and it felt alright, but not great. I still had more creep than I wanted and the pull was still a bit gritty.

I took a bit more off, but this time I trued the stone up before I got started. I don't have a really good way to measure how much material I removed, other than what I dialed in on the mill, but I don't have a really good before and after measurement. After grinding, I gave all the contact surfaces of the hammer and trigger a good rubdown with the hard Arkansas stone, cleaned everything up well and then hit them with several coats of dry lube. I'm going to run it without any oil and see if it helps keep gunk from sticking in there. I also tweeked the trigger spring to lighten things up a little.

The trigger is now friggin' awesome! Almost no creep, smooth as anything and as close to a "glass rod" break as I'm comfortable attempting. There is a very positive engagement between the trigger and hammer -when I pull the trigger I can watch the hammer get pushed back before it breaks. I think this engagement might be excessive, but I haven't figured out a way to change the angle on the hammer to reduce it.

All seems safe still - it looks like I still have enough engagement to keep things from going full auto, but I'm still going to be cautious when I do try and run it.

 

[Eddie Gunks]

Nice.

Keep us posted on the longevity of it. I would be concerned with having removed the hardened steel part with your stone.....leaving mild steel to wear more easily.

 

[Podmonkey]

While I admire the do it yourself spirit I'd have figured it was easier and more effective to simply swap in a new trigger group.

 

[gun_slinger_boy]

Does anyone actually like milspec triggers? I actually like them better than those smooth super slick things. It has a more predictable break in my opinion.

 

[Podmonkey]

Does anyone actually like milspec triggers? I actually like them better than those smooth super slick things. It has a more predictable break in my opinion.

I fail to see why anyone would prefer a heavy, gritty trigger. "Milspec" is a loose term when applied to trigger feel. For example the standard trigger on the Daniel Defense rifle has been described as a "milspec" unit but I thought it had a pretty clean break with just a bit of grit and creep. There was also some take up and overtravel as well but it was a significantly better feel than I remember the trigger of an actual M16A2, which I recall as being shittin' awful! Very heavy pull with tons of grit and creep. It took a lot of concentration to overcome and not pull your shots.
Nonetheless I replaced the stock trigger of the DD with a relatively modestly priced unit from Hiperfire, the EDT. Significant improvement, no takeup or over travel a 4.5lb pull with just a touch of grit that smoothed out with use and a very crisp break. Its not a match trigger but works very well on a carbine intended for practical use.

 

[kev74]

Nice.

Keep us posted on the longevity of it. I would be concerned with having removed the hardened steel part with your stone.....leaving mild steel to wear more easily.

The DPMS parts look like they're made of sintered metal. That stuff is usually uniform in hardness all the way through. If they're going to save money by using playdough for parts, they're not going to spend money on a separate heat-treat step. I am curious to see if it holds up though.

I've been using Teflon dry lube on the trigger parts on the .22s with very good results. I hope it works as well on the AR. So far, it feels great.

While I admire the do it yourself spirit I'd have figured it was easier and more effective to simply swap in a new trigger group.

I've got a garage and workshop full of tools. Every hour I play with them is an hour I didn't sit on the couch watching crappy tv. Easy has nothing to do with it.

The worst that happens is I scrap the parts and buy a new trigger group. I made my peace with that before I started.

 

[Podmonkey]

The DPMS parts look like they're made of sintered metal. That stuff is usually uniform in hardness all the way through. If they're going to save money by using playdough for parts, they're not going to spend money on a separate heat-treat step. I am curious to see if it holds up though.

I've been using Teflon dry lube on the trigger parts on the .22s with very good results. I hope it works as well on the AR. So far, it feels great.


I've got a garage and workshop full of tools. Every hour I play with them is an hour I didn't sit on the couch watching crappy tv. Easy has nothing to do with it.

The worst that happens is I scrap the parts and buy a new trigger group. I made my peace with that before I started.

Tinkering is cool and comendable.

 

[kev74]

Tinkering is cool and comendable.

I concur!

 

[thegatman]

Just make sure that the sear face is still at the proper angle. You can try changing out the springs too.

 

[gun_slinger_boy]

I fail to see why anyone would prefer a heavy, gritty trigger. "Milspec" is a loose term when applied to trigger feel. For example the standard trigger on the Daniel Defense rifle has been described as a "milspec" unit but I thought it had a pretty clean break with just a bit of grit and creep. There was also some take up and overtravel as well but it was a significantly better feel than I remember the trigger of an actual M16A2, which I recall as being shittin' awful! Very heavy pull with tons of grit and creep. It took a lot of concentration to overcome and not pull your shots.
Nonetheless I replaced the stock trigger of the DD with a relatively modestly priced unit from Hiperfire, the EDT. Significant improvement, no takeup or over travel a 4.5lb pull with just a touch of grit that smoothed out with use and a very crisp break. Its not a match trigger but works very well on a carbine intended for practical use.

I guess the terms heavy and gritty are subjective. Every gun that I've owned that has had a "heavy/gritty" trigger has improved over time and is not even noticeable after a while. I can't remember if my ak47 had that when I first got it but over 10 years later it's just fine. Now don't get me wrong. A nice lighter smoother trigger like on my 1911's is nice. And probably my nicest trigger of all my guns on my S&W 629 performance center is nice feeling too. But does it actually help my shooting? I don't know. Not enough to spend crazy money on trigger jobs/groups at least. I get a gun, shoot it, get used to it and then it's all good.

 

[Eddie Gunks]

Just make sure that the sear face is still at the proper angle. You can try changing out the springs too.

@kev74

I have a couple of the red colored hammer springs from an EDT kit. They are not the lightest spring. But they’re probably better than mill spec.

P.m. me if you want it.

 

[Mosinitis]

There aren't any good trigger jobs on stock AR triggers that will last. It has to do with how the triggers are heat treated. If you want a descent trigger get an aftermarket trigger like Geissele.

 

[Podmonkey]

I guess the terms heavy and gritty are subjective. Every gun that I've owned that has had a "heavy/gritty" trigger has improved over time and is not even noticeable after a while. I can't remember if my ak47 had that when I first got it but over 10 years later it's just fine. Now don't get me wrong. A nice lighter smoother trigger like on my 1911's is nice. And probably my nicest trigger of all my guns on my S&W 629 performance center is nice feeling too. But does it actually help my shooting? I don't know. Not enough to spend crazy money on trigger jobs/groups at least. I get a gun, shoot it, get used to it and then it's all good.

A nice trigger is something of a luxury given that even a terrible trigger can be adjusted to. I managed to routinely qualify expert with the horrible trigger of the issue M16A2. But what is wrong with indulging in a bit of luxury from time to time? One thing I will say about my trigger upgrade is that it makes accurate double taps pretty easy. It's a fairly fast trigger too.
My policy is to get used to a gun in its stock configuration before I change anything on it.

 

[zzrguy]

Update...

I took it to the range and it felt alright, but not great. I still had more creep than I wanted and the pull was still a bit gritty.

I took a bit more off, but this time I trued the stone up before I got started. I don't have a really good way to measure how much material I removed, other than what I dialed in on the mill, but I don't have a really good before and after measurement. After grinding, I gave all the contact surfaces of the hammer and trigger a good rubdown with the hard Arkansas stone, cleaned everything up well and then hit them with several coats of dry lube. I'm going to run it without any oil and see if it helps keep gunk from sticking in there. I also tweeked the trigger spring to lighten things up a little.

The trigger is now friggin' awesome! Almost no creep, smooth as anything and as close to a "glass rod" break as I'm comfortable attempting. There is a very positive engagement between the trigger and hammer -when I pull the trigger I can watch the hammer get pushed back before it breaks. I think this engagement might be excessive, but I haven't figured out a way to change the angle on the hammer to reduce it.

All seems safe still - it looks like I still have enough engagement to keep things from going full auto, but I'm still going to be cautious when I do try and run it.

What did you get the trigger pull down to?

Joebob fix? The Grip Screw Trigger Adjuster?

the screw and spring just shot it the other day 4 touching hole at 50 1in group at 100.

I do like DPMS MILSPEC trigger over most others MILSPEC I've put in other ARs. Just put together my NYGF lower with one and it feels pretty good a little heavy 7 to 8lbs but clean no real creep. I may order another Joe Bob's kit

 

[kev74]

What did you get the trigger pull down to?

I haven't measured it yet. It was kind of late when I got it back together last night. I'll try and do it tonight.

I wish I would have documented everything better - before & after, and how much material I took off.

 

[Podmonkey]

I do like DPMS MILSPEC trigger over most others MILSPEC I've put in other ARs.

See? You just made my point. If triggers were truly "milspec" they'd all be the same kind of awful but they're not. Some are better than others.

 

[Mosinitis]

It's surface hardened metal. You remove the outer layer and you are dealing with soft engagement surface. This was already learned years ago and the process was abandoned. It doesn't hold up to use.

 

[kev74]

It's surface hardened metal. You remove the outer layer and you are dealing with soft engagement surface. This was already learned years ago and the process was abandoned. It doesn't hold up to use.

We'll see. The original finish looked like it was done on a belt sander, and there was no sign of case hardening or surface hardening of the metal. After grinding on it, I'm fairly certain this stuff is uniformly hard throughout.

 

[GUNSICK]

Does anyone actually like milspec triggers? I actually like them better than those smooth super slick things. It has a more predictable break in my opinion.

You should give a 2 stage trigger a try.

 

[Podmonkey]

You should give a 2 stage trigger a try.

Depends one what the rifle is being used for. Single stage works better for aimed rapid fire, double taps ect.

 

[tony]

If you're concerned about grinding through the case hardness of a part you might try a product called " Cherry Red ". It is supposed to be a product like
" Kasenit " for case hardening parts. From what I have read Kasenit was/is a better product but is no longer available.

 

[zzrguy]

See? You just made my point. If triggers were truly "milspec" they'd all be the same kind of awful but they're not. Some are better than others.

The spec is the spec there is tolerances build in to the spec. I'll bet the DPMS LPK in a DPMS lower would feel the same in a bunch of their lower but fell different in say a Spike lower as both company tooling is defferent.. But all the parts are with in tolerances.

 

[Eddie Gunks]

The spec is the spec there is tolerances build in to the spec. I'll bet the DPMS LPK in a DPMS lower would feel the same in a bunch of their lower but fell different in say a Spike lower as both company tooling is defferent.. But all the parts are with in tolerances.

Milspec means “loosey-goosey”

It means it will “be close”

Milspe is not tight tolerences. It is the opposite.

 

[zzrguy]

Milspec means “loosey-goosey”

It means it will “be close”

Milspe is not tight tolerences. It is the opposite.

Yes 100% .
What I ment was that even thou its MILSPEC one manufacturer hammer pivot hole maybe .001 forward and .0005 up but everything they make is to that spec and all in MILSPEC.
This is why I like to match my Uppers and Lowers.
Then you have the whole AR10 bullshit MILSPEC or DPMS(I will say me DPMSs are tite and run flawlessly but I never own or fired any other AR10s).

 

[Dank27]

Only "trigger job" worth doing is timney or geisselle.