greyling,
do you know of a YouTube DIY video with your trigger work? if not why not make one?
-kBob
I do not know of a video, and I don't know how to make one. certainly not how to edit one together. but, maybe this will be helpful:
first, watch this video on how the trigger works.
Note how the springs apply tension, how the front of the trigger bar is the sear and the hammer has a notch in it. Also how the disconnector grabs the hammer to keep the gun from going full auto.
then, realize that the milspec ar trigger is garbage because
a) it has WAY too much spring tension on the hammer/sear interface to ensure 100% ignition under all circumstances, which makes the pull heavy, and
b) it has WAY too much engagement between the hammer hook and sear surfaces, leading to a bunch of creep.
this is essence of every trigger job on every gun. less engagement and less tension on the engagement surfaces.
***********DISCLAIMER. I AM NOT A GUNSMITH. YOU ARE PROBABLY NOT A GUNSMITH. PROCEED AT YOUR OWN RISK ************ that said, I have done this to a dozen or so AR's and have never had a problem.
so, lets deal with them in order: to deal with the pull weight, we need less spring tension. you can buy springs, but why? Clip and hammer spring and bend the trigger springs at about a 30 degree angle like this
https://imgur.com/a/bXHN7Kd
now, sear engagement. this would be better with a video, but in this picture,
https://imgur.com/a/fe82Fdl we are going to use a set screw run up the grip screw hole to push the back up the trigger bar up, which, like a see-saw, will push the front down, reducing sear engagement. the easiest way to do this is to have the gun assembled and on safe, then screw in until the bar hits the safety, then back off until the safety can be turned. This will improve the trigger some, and requires nothing fancy on your part. (
Note: if you have one of those cheap anderson lowers like most everybody has, the screw hole is not tapped all the way through to the receiver and you'll need a tap and die set to finish threading the hole.)
To get a truly nice trigger require a bit of work.
https://imgur.com/a/tAO2yD8
Install the hammer and trigger (no need to install disconnector at this juncture, and it just gets in the way). pull the safety and cock the hammer. run the set screw up the grip until the hammer trips. then back off the set screw until you have a balance of safe engagement and nice pull that you are comfortable with.
Now, look through the safety hole. Uh-oh, there is the back end of the trigger bar in the way of installing the safety. You will need to file/dremel this away.
Take a pencil and scribe a line ON BOTH SIDES showing where you need to file. Pull the trigger group out file to the line, reinstall everything but the disconnector. Does the safety work? if yes, you win. If no, you took too much off you bozo. build it back up with jb weld and try again. You should now have a really nice trigger. Depending of you skill, luck, and technique, you might have 3lbs, basically no creep, and virtually no overtravel, depending on how much clearance is between the safety and the filed back of the trigger bar. (you may have to back off a little on the set screw hereto lower the back of the trigger bar and reinsert the safety. You also need the hammer cocked to reinsert the safety. There is a lot of test fit and check your work here the first time you do this. go slow. it is easier to take more off than put it back on)
BUT WAIT! there's more! remember the disconnector? when you install it now, you will have a problem. You angled the whole trigger bar forward, permanently moving the disconnector hook forward enough that it will not release the hammer. Easy fix. Install disconnector, cock hammer. Take note of how much of the disconnector nose is overlapping the hook on the back of the hammer, and remove it. It doesn't have to be exact. When you pull the trigger it will move the disconector far enough forward to catch the hammer unless you take a ton off. Test function. Note: if you take too much off the hook and your hammer won't catch on it, you now have a full auto gun for a few rounds. Easy fix. Pull the disconnector, file some on the bottom of the nose as seen in the picture,
https://imgur.com/a/QZyzRap this will allow the hook to move forward again. check and fit until you have proper function.
whew, that was long. it sounds more complicated than it is. If it all works, you win, if it doesn't, well, many of you were going to buy a drop in trigger anyway, you have lost nothing. Hopefully this was helpful and not confusing.
I only run tula, wolf, and S&B primers in my AR's, and I have never had a light strike with my lightened springs. If you do, you can try the JP speed hammer mod. cut the big hook off the hammer as seen here
https://imgur.com/a/huVe0FI
I have attached this as a word doc as well. the pictures are all in the right spots in it. I couldn't make them appear in the posting. Mods feel free to make it look pretty.
