Home-made trigger job

[gnatshooter]

Friends,

 

I just completed a 'trigger job' on my DPMS LR-308T. It was a frightening experience, but I'm happy with the result.

 

I actually liked the factory trigger in most ways. The pull was long, which was OK with me, which helps make the hammer trip 'a surprise', which I was taught was WWII-era sniper discipline. The trouble was, the pull was nasty and gritty. As one author somewhere aptly described it, pulling the trigger was "like dragging a hoe over gravel."

 

I watched enough YouTube videos and read enough stuff online to believe I could take down the trigger group and polish the parts where the trigger meets the hammer.

 

Things came apart fairly normally, except for my fright when I discovered I had to remove the safety selector to get the trigger out. Searching online I eventually discovered that this meant pulling off the grip, which I did, and two springs and two detents fell out. I have had bad experiences with springs.

 

Once things were apart I took my new sharpening stone out of the package and gave up on it. The stone was a waste, except that I can use it on kitchen knives. The problem was too rough a grit, so I went instead for some #400 grit sandpaper. Which I already had. Geesh.

 

After 45 mins. of polishing the sear of the trigger I figured it was as bright and smooth as it would ever be. I looked at the notch in the hammer, and tiny as it was, I figured I wouldn't be able to do a thing with it, even though one video guy recommended filing it with a tiny file. Which I had.

 

But I figured, a smooth sear should be good enough for the whole mechanism. Putting the trigger group back together, I found that my new 1/8" punch for pin removal was my best investment, as it held things lined up for me while I pushed the pins back in.

 

It was maybe a good thing I noticed when they came out that the extra groove on the pin ends went on the right-hand side of the rifle. Nobody mentioned that in the videos, but I figured they should go in the way they came out.

 

My second fright was finding that, with the trigger, disconnect and hammer back in place, the safety selector wouldn't go in the hole. After lots of fooling, turns out if you cock the hammer back, it goes right in. Hooray for that. And you can imagine my relief when the detents and springs went right into place for the safety selector and takedown pin.

 

The final result is, the trigger is actually a bit lighter -- since there's less friction in the parts where the 'gravel' used to be. The pull is now smooth, and though the trigger doesn't 'break like glass', it's sharp enough.

 

Overall, I'd say, if you don't want to blow $200 or so for a better trigger, you should consider doing a 'home-made' trigger job. I'm happy with the result.

[seasprite]

I tried to a trigger job once on my DPMS and failed miserably. In short it failed almost all safety checks just a slight bump on the stock and the hammer fell. I have a feeling the only way to keep it from firing full auto was to hold the trigger back and let the disconnect hold the hammer, never did a live fire with it just got an Giessele trigger in it and never looked back. Gave that trigger to my Pastor who is also an armor for the police dept. to play with and have some fun.   

 

Glad you were able to the job without going to far but as for me Giessele all the way.

[gnatshooter]

I tried to a trigger job once on my DPMS and failed miserably. In short it failed almost all safety checks just a slight bump on the stock and the hammer fell.

 

I didn't do any 'safety checks' and would like to know more about them. All advice is of course welcome, safety is a top priority.

 

Thanks!

[seasprite]

SAFE

Pull the charging handle to the rear and release. Place the selector on SAFE. Pull the trigger, and the hammer should not fall. SEMI

Place the selector on SEMI. Pull the trigger and hold to the rear. The hammer should fall. Continue to hold the trigger to the rear, pull the charging handle to the rear, and release it, Release the trigger with a slow, smooth motion until the trigger is fully forward. The hammer should not fall. Pull the trigger. The hammer should fall.

 

I can't find what I was looking for but I remember also something about bumping the stock with your finger off the trigger and the hammer shouldn't fall.

Also let the bolt slam home on an empty chamber and the hammer shouldn't follow. 

[gnatshooter]

Place the selector on SEMI. Pull the trigger and hold to the rear. The hammer should fall. Continue to hold the trigger to the rear, pull the charging handle to the rear, and release it, Release the trigger with a slow, smooth motion until the trigger is fully forward. The hammer should not fall. Pull the trigger. The hammer should fall.

 

I did that. When I release the trigger, there is an internal 'click' that I can feel in the trigger group. Then when I pull the trigger, there is a second 'click', which seems like the hammer is falling. I think maybe the first click is the disconnect releasing, is that right? If that's right, I passed all the tests.

[texas30cal]

I have had good luck using the lighter jp spring kit but the original hammer spring (the jp hammer spring gives light strikes), using a rra single stage as a starting point (excellent quality) I stone the sear surfaces with some inexpensive stones I got from Brownells (the goal is to improve surface finish and to NOT change angles or round the corners at ALL), I do the set screw trigger stop (check out youtube) to help with preloading the trigger but be very careful here because trying to make the travel too short can make it DANGEROUS. The beauty of this is you can learn quite a bit and it costs very little, if it doesn't work or you just don't like it , well it cost very little and hopefully you learned something and you haven't done anything you can't put right back the way it was.

[Rsquared]

Gotta be careful with the trigger assemblies. Like Tex said......to polish is one thing. To change the geometry is another. A file can seem pretty barbaric.....when emery paper (fine grit sand paper) can do the job.

 

And for all the junior G-men out there......we're talking about lightening a trigger. Not making an illegal full-auto trigger assembly...................................just to clarify.

[seasprite]

One other safety note when test firing only load a max of 2 to 3 rounds until your satisfied that the trigger is not going to go full auto on you.

[98Z5V]

 

 

And for all the junior G-men out there......we're talking about lightening a trigger. Not making an illegal full-auto trigger assembly...................................just to clarify.

Just polishing surfaces won't lighten trigger pull, but it may seem like it once it feels "smoother." 

 

Changing engagement angles with change trigger pull weights.  Or ruin a trigger.

[texas30cal]

Forgot to mention that definitely don't load a full mag, I usually only load 2 at a time and do this several times. For polishing I personally wouldn't use any emery paper, it makes it too easy to round things off, maybe just a touch at the end but that would be it, it's all about keeping things straight and square and not changing angles as far as safety goes. I have found that anti seize ( I have the copper type) works well for lube on the sear surfaces. And do your safety checks to make sure the disconnector is working.

Edited September 18, 2013 by texas30cal