AR Pistol Grip Screw Trigger Adjusters

[XD45 7,124]

I admit I haven't been much of an AR guy up to now and so it's not surprising that this little mod escaped me up until last week.  I stumbled across this when looking at triggers for the AR pistols (don't call them sbrs).  Many of you probably know about this already but for any that don't, the grip screw trigger adjuster is a cheap and easy improvement of the mil-spec trigger.

 

I got them for $10 each (including allen tools) off of eGay.

Edited December 24, 2014 by Darth Saigus

[poolingmyignorance 2,191]

I just bought a whole box of 100 1/4"-24 set screws for $10 from Grainger a few years ago I've used on a few builds. It's an excellent little mod that saves a ton of time, and with a little bit of 400grit sand paper you can make a truely match trigger witht this.

Note though that if you have a SPIKES lower, you might also want to invest in the 1/4x24 tap as they seldom tap all the way through the PG hole.

[XD45 7,124]

There are two ways of doing this mod.  Using the short 1/4-24 set screw like you did and using grip screws that have been drilled and tapped with an adjuster screw inside them.

 

 

[tim2shu 48]

Is this for over travel?

[BigChongus 765]

Reduces creep I guess? I'll look into these if I decide I hate the DD trigger.

[poolingmyignorance 2,191]

It requires you to modify the trigger/saftey, but allows you to adjust the travel/reset to exactly where you want.

[XD45 7,124]

You do not need to modify the trigger or safety.  It eliminates take-up and reduces creep to near zero.

 

I did it to both AR pistols and both triggers are greatly improved.  Both are mil-spec triggers.  Pull weight is not reduced much but the spongy and gritty creep is gone. 

 

Replace the grip screw with the adjuster, and get it tight.  You don't want it coming loose.

 

You put the safety on and tighten the adjustment screw until the back of the trigger touches the safety.  If it's too tight the safety will be difficult to move.  Back it off 1/10th of a turn.  Use a drop of Loctite to make sure it stays.

 

If you want to see how it will work, pull the trigger of your AR with the safety on.  Hold the trigger in place and take off the safety.  Then pull the trigger and you will get an idea of how it works.

 

I have a third adjuster for my M4gery but I'm going to hold off putting it in until I get the new grip.  Obviously the adjustment would change if you change your grip.

Edited December 24, 2014 by Darth Saigus

[poolingmyignorance 2,191]

I should rephrase that.. you don't HAVE to modify the saftey..but you can get some fucking awesome results doing so, WITHOUT comprimising integrity of the saftey mechanism.

[HB of CJ 1,263]

Years ago we just used common longer pistol grip screws with Allen heads alternating flat washers with lock washers under the head. Ground down the ends to the exact or nearly so length, then adjusted to suit using blue Locktite. Worked OK. FWIW it was a common approach about 25 years ago. We also set up the ejectors for South Paws using a home made smaller C-clamp ejector tool ground down on the end to fit over the bolt head. Just stuff we used back then. HB of CJ (old coot)

[dayofruin 425]

I just ordered a set of two to try out. $7.99 shipped.

[tim2shu 48]

I just ordered a set of two to try out. $7.99 shipped.

Were at

[dayofruin 425]

 

I just ordered a set of two to try out. $7.99 shipped.

Were at

Pm sent

[dayofruin 425]

I ordered a second style for $12. They're cheap enough to give them a try. If I don't like them, I Can probably resell them on facebook or something.

[james lambert 3,059]

It should be noted that the grip screw in an AR15 is a 1/4 x 28 tpi  not 24 tpi

 

I have been doing triggers in ARs for 30 years, in the old days I would drill and tap a hole in the grip boss behind the grip screw hole.

Tap that hole to 10 x 32 and use a set screw with a nylon locking element.

when we started manufacturing AR15 receivers I added that feature, now several other companies also add the feature.

The set screw can be adjusted to raise the tail of the trigger, effectively pulling the trigger rearward and reducing the engagement of the primary sear.

Keep in mind when you raise the trigger you also push the secondary sear or disconnector forward as well.

If you raise the trigger very much the disco will not disengage from the hammer when you release the trigger (wont reset)

If so the disco would have to be cut back to a proper engagement value with the hammer.

When working with quality AR15 lowers and FCG parts very little slop will be present between the trigger tail and the safety.

adjusting the play out of that fitment is a nominal adjustment.

when actually reducing primary engagement to make a crisp short travel trigger pull...Adjusting the safety and the disco will be necessary

 

Note that this should only be done by an experienced gunsmith    its easy to make an unsafe modification if you dont know what you are doing .

[HB of CJ 1,263]

Also if you want to fool around with your hammer and trigger engagement areas, remember that the heat treat there is only about .002 thick. Cut through that you will get a sweet 4-5 lb trigger, but it will only last about 500-1000 rounds. Then doubling becomes a concern with the resulting jail time with Big Bubba and his bigger boyfriends. Just a thought. HB of CJ (old coot)

[poolingmyignorance 2,191]

Also if you want to fool around with your hammer and trigger engagement areas, remember that the heat treat there is only about .002 thick. Cut through that you will get a sweet 4-5 lb trigger, but it will only last about 500-1000 rounds. Then doubling becomes a concern with the resulting jail time with Big Bubba and his bigger boyfriends. Just a thought. HB of CJ

If you've ever tried sand .002" of hardened steel, with 400 grt paper by hand..you'll realize how much margin of error you have. Your gonna be there for a WHILE.

in case you didn read.  SANDING BY HAND. NOT POWER TOOLS.

[HB of CJ 1,263]

Exactly correct and thank you. We used mundane 800 grit stones. I was alluding to others who may not have that level of experience. HB of CJ (old coot)

[poolingmyignorance 2,191]

Exactly correct and thank you. We used mundane 800 grit stones. I was alluding to others who may not have that level of experience. HB of CJ (old coot)

I had to emphasis because it's really tempting to grab the dremel after the first reassembly doesn't show the desired results. But it's ultimately worth it, and you'll begin to understand why a match trigger starts at $200.

Jim, thanks for the correction.

[dayofruin 425]

Did this mod today. Took a hair too much off the back of trigger and now have a super short pull and reset... While the rifle is on safe. I'll order a couple new trigger parts and start over.

[XD45 7,124]

That's why I didn't modify the parts.  I'm satisfied with the results.