Power's Custom Series 2 Jig and the AR-15

[seagiant]

Hi,
I built a DPMS LR-308 lower for my rifle and was not real happy with the stock trigger! I did not want to spend $250 on a drop in so decided to see what I could do.

When I bought my Powers Series 2 jig used it came with one adapter which was for the AR-15/M-16 rifle. At the time I did not even own one but set it back for later. The jig is interesting as you can set it up with the adapter to work on the trigger and hammer.

I set the jig to first stone/polish the surface of the parts that interact with each other. Then I set them up to cut down the height of the working faces. This is where you get rid of "creep" and with the polished faces you get the smoothness. I cut a break away angle on the trigger sear to help with the creep and to enhance the feel and operation of the break when it releases the hammer.

I will have to admit that after the trigger job I probably do not have as good a trigger as a $250 drop in but most of the creep is gone and the trigger is smoother. I left a small bit of creep to see how it feels after break in. Did not want to go to far. As a side note these parts are still "file hard" and should last for a long time. Here are some pics of the jigs in use.

[andremajic]

You can also change the primary sears angle to make it slightly less "positive", which will reduce the trigger pull weight. Don't overdo it, as you can make it unsafe it you go overboard.
Generally just dragging the primary sear at a 90 degree angle across a medium fine stone a couple times will do the trick.

If you slowly pull the trigger back and watch the hammer, the hammer will slightly move back. That is a sign of a positive engagement.

A neutral engagement is generally frowned on for most guns because after a long time of wear, it "could" develop into a negative engagement. This is where the hammer doesn't move back at all when you pull the trigger, and the sear angle exactly matches the hammer notch angle.

A negative sear engagement is very dangerous and is responsible for most of the "bump fires" that happen when people drop their guns.

If any of this seems too vague or doesn't make sense, I would recommend renting the AGI video that shows how to do an AR trigger. It's like, 10 bucks. (He uses a belt sander to remove material. Not recommended, as he makes a mistake and shows how to correct it after rushing the job.)

If you take your time and think thru each time you remove metal, you will LOVE the resulting trigger job. If you rush the job, you'll be buying more parts.

I wish I had that jig....

[seagiant]

Hi,
Thanks,I have the series 1&2 jig from Ron Powers. The adapters have gone up in price lately but are still a lot cheaper than a trigger job from a smith!

The guy in the DVD probably used a belt sander because there is A LOT of material to take off the hammer hook on a regular AR-15 hammer. I just used my stone but it took a while and I was putting it back in each time to check it. Slow admittedly but I now have a pretty good trigger.

I do not change MAJOR angles,I have found if you polish the factory angle,cut down the hammer hooks to get rid of creep and then polish the sear and put in a break away angle, you usually end up with a very nice improvement over the factory and it is still safe!

If you enjoy working on triggers you need to do yourself a favor and get both these jigs they are a pleasure to use and your trigger jobs will improve greatly!

[akajun]

hate to bust your bubble, but that trigger job will not last. As per mill spec, ar triggers are case hardened. When you start stoning on them , if you go past a few thou of polishing, you expose the soft metal. You will get about 500 rds or so out of the trigger and it will go to mush. There is a reason that Frank white used to re heat treat the military triggers he used to modify to make 2 stage match triggers back in the day.
Buy a RRA 2 stage for $100, or one of geiselle's lower priced triggers.

BTW I have both trigger jigs and they are great, just not worth a damn for an ar in the long run.

[seagiant]

Hi,
Well....my bubbles are doing fine! I've heard those stories and was watching for that but like I said in my original post my hammer and sear are still file hard and thats plenty hard in anyones book!

[W.R.Buchanan]

Lots of misunderstanding about "Case Hardening"

Case hardening now days is done in a inert gas oven and when brought up to temp, about 1500F Acetelyne gas is injected into the oven. This permeates all of the surfaces of the parts equally.

The longer the gas is in the oven before it is purged out, the deeper the penetration. And they have this sussed out so they can give you nearly exactly .020 or .030 or .060 as you require.

Very few case hardening jobs are less than .020 deep as it is more difficult to control the depth as accurately on the low end due to the short periods of time the gas is left in the oven, so this usually turns out to be a more is better type of operation. It is also a very efficient process.

In the distant past case hardening was done by heating the metal the bright red and dipping it in a can of carbon powder and then reheating and redoing the process several times just to achieve minimal penetration. The gas method is much more effective. However in the shop the old method could still be used with a Oxy/acet torch to correct a FU.

You would have to get up really early in the morning to stone thru .020 of case that is around 65 Rc,.

Also you can see when you do go thru the case as the metal is no longer finely finished and shiney, and gets a dull appearance like filing soft steel.

The easiest way to tell if you have gone thru is to hit it with a file. And if the file slides over it then it is still hard.

If the file cuts, you done screwed up.

Randy

[andremajic]

I'm gonna keep my eyes open on ebay for one of those...

[KCSO]

I have never stoned throught the hardness on an AR style sear or hammer, but I suppose it COULD be done. I willl add that if you want to take up the slop you might consider adding a 1/4-28 set screw ubder the grip screw. Run the threads up to the frame with a 1/4-28 tap and then put in a set screw with a nice tapered top. This willl bear against the bottom of the trigger bar and by carefull adjustment you can take out a lof of the overtravel. You will need to be carefull and check so that the safety dosen't bind and that the gun doesn't doouble on you. When you have the sweet spot fond be sure and use thread sealer to lock the set screw in place.

[seagiant]

Hi,
Yes, I'm familiar with that process. Actually the grip screw is 1/4x28,and what you do is drill and tap a 6x32 hole in the end and then set with the 6x32 headless set screw. This is best done on a lathe to keep everything straight and true. I think JP Enterprises sales this for $40! A little steep to me for 2 screws!

[W.R.Buchanan]

Greg: now come on,,, it is pretty derned hard to drill & tap that hole in a screw.

I figure the allen wrench is worth $39 of the $40 in that deal.

Randy

[David2011]

SOME AR triggers and hammers have a thin case hardening but not all do. The guys in the shop at Olympic Arms told me they stone their triggers and hammers every day for their premium guns and that their parts are hardened throughout instead of case hardened. If in doubt, ask the manufacturer.

On the ARs I've done trigger jobs on, I tapped the grip screw hole all the way through and put a 1/4x28 set screw in to adjust the takeup. The factory springs were replaced with JP trigger and hammer springs. The surfaces were stoned with Brownell's ceramic stones which give a beautiful finish. The triggers had to be cut to allow the safety to fully engage without allowing ANY movement with the safety engaged. It's a royal pain and still not as good as some replacement triggers but still a huge improvement over the original trigger pull.


I've done just enough AR trigger jobs to decide it's worth it to buy a replacement trigger.

Just my opinion. . .

David

[seagiant]

Hi Randy,
If I could make and sale those screws for $40 a pop on my old Clausing, I'd never get my feet wet again!!!

[KCSO]

The older method was two 1/4 28 screws on on top of the other but what yo have will work too. As to $40.00 that's more than I get for the whole job!

[seagiant]

Hi,
Ok,now I get it! Sorry,I only heard of the 6x32 tapped into the end of the screw! I guess the 1/4x28 only trick would be better for folks without a lathe! I'm a little new to the AR platform,I've always favored M-14's,Garands and FALS.

Wonder how long the screw trick has been around???

A bad pic of my DPMS LR-308 build! With all MAGPUL furniture! An AR-15 buddy of mine calls it the "BEAST"!