Fine tuning an AR trigger - worth the effort??

B

BumbleBug

New member
I've built my AR15 with PSA lower parts & it shoots & functions pretty good for a bargain rifle. The standard trigger is really HEAVY & has a bit of roughness at the end of pull. I understand how the trigger/hammer works & I've read articles & watched videos on polishing, stoning, "bobbing" the hammer, lighter springs, etc.

Is it worth the effort? Can I really get a decent trigger by working over the standard assembly & adding a $10 spring kit?

Or...

Is it better just to spend the $75 up for a drop-in trigger?

TIA...

...bug
 
To me- it's better to go with a match trigger. Reason being is liability- or better said "Risk". The hardening is pretty thin on those parts, so I'm told. Now I could probably shoot the thing fine for years ( or once or twice), but how am I supposed to feel if it goes bad while a family member is shooting it? I'll work on and tinker at a lot of things- but I feel like I just don't know ALL the details well enough to tinker with an AR trigger when such fine examples are available from folks who do have a good grip on the processes.
 
AR triggers

Are notorious for thin hardening on hammer and sear surfaces. I have never worked one that did not go bad over time due to wearing through the case hardening. Aftermarket hammers and triggers of the original pattern which are made of tool steel and hard all the way through will last when smoothed. Up front expense proves worth it in the long run.
 
I have always put in the little extra effort to improve the triggers on my guns.
I have had mixed success cleaning up my AR GI triggers from just "Ok" improvements to "Wow that is a pretty nice $10 trigger"!

My last effort was a PSA MOE lower parts kit trigger and it turned out great. I still plan to upgrade to a "Better" trigger but, this works for now.
 
As other's have already stated, it's not worth the fuss to fool with stock trigger. Best to go with a match trigger and drop that in and be done with it.
 
On one, we built using the JPS 3.5 springs- and it made a very discernable difference.

http://www.jprifles.com/buy.php?item=JPS3.5

I would start there- it's a very cheap investment, and will give you tangible results. Personally, I wouldn't put any more effort into an inexpensive trigger group. Replacing the trigger and hammer springs may give you a decent "enough" trigger- depends on what you're looking for.

On another rifle (an AR-10 with a lousy trigger group), we replaced it with the complete JP Fire Control system. Fantastic results, 3.5 lb pull weight- but it is not "drop-in" by any means, and requires timing (grinding) the disconnector.

http://www.jprifles.com/1.4.8.2_fc.php

If you feel comfortable doing some minor gunsmithing, this is a relatively inexpensive way to go compared to getting "drop-in" triggers from Timney or Geissele.
 
You don't learn anything by buying a trigger and dropping it in. If you're ok with that, do it up.

If you want to try it yourself, give it a run. What's going to happen? You have to buy a new trigger? Hm. See step 1.

Thin hardening? So what. Harden and then temper it yourself. It's not rocket science.
 
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You don't learn anything by buying a trigger and dropping it in. If you're ok with that, do it up.

If you want to try it yourself, give it a run. What's going to happen? You have to buy a new trigger? Hm. See step 1.

Thin hardening? So what. Harden and then temper it yourself. It's not rocket science.
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How do you know if you ruined the hardening? How do you harden it yourself?
 
High-carbon steel is hardened when it reaches it's Curie Temperature (the point it loses magnetism).

There's a bunch of ways to harden, quench and temper steel but here's how I'd do it.

1)Suspend the piece by one end, using a fairly large magnet over a bucket containing a solution of 1 gallon water, 1 pound salt and 8oz of Dawn dish soap.

2)Start heating the part slowly at first and once it's hot, apply high-heat directly. Use two torches if necessary.

3)When it loses it's magnetism and falls in the solution, it will be hardened and quenched.

Tempering is trickier. A good fryer can do it. You need 400F. Peanut oil has a high enough flash point. It can also be done in an oven if it holds the temperature very well. Put the part in the cold oil, turn the fryer on, heat it to 400 and give it about 40 minutes (for a trigger piece). You need about 20 minutes per 1 inch cross-section. Turn the fryer off. When the oil is cool, take your part out and you're done.
 
High-carbon steel is hardened when it reaches it's Curie Temperature (the point it loses magnetism).

There's a bunch of ways to harden, quench and temper steel but here's how I'd do it.

1)Suspend the piece by one end, using a fairly large magnet over a bucket containing a solution of 1 gallon water, 1 pound salt and 8oz of Dawn dish soap.

2)Start heating the part slowly at first and once it's hot, apply high-heat directly. Use two torches if necessary.

3)When it loses it's magnetism and falls in the solution, it will be hardened and quenched.

Tempering is trickier. A good fryer can do it. You need 400F. Peanut oil has a high enough flash point. It can also be done in an oven if it holds the temperature very well. Put the part in the cold oil, turn the fryer on, heat it to 400 and give it about 40 minutes (for a trigger piece). You need about 20 minutes per 1 inch cross-section. Turn the fryer off. When the oil is cool, take your part out and you're done.
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1 lb of salt and dawn dish soap??? Where did you get that recipe?

BTW, as I re-read this I see it sounds like I'm being a smart a$$, but I don't mean it that way, I'm curious to know.

Also, how do you know it lost its temper and hardness?
 
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It's not my invention. It (or something similar) was invented by Rob Gunter at Los Alamos National Laboratory.

How do you tell? Personally, I wouldn't worry about it and if I was I'd just reharden and temper it.

There's no nondestructive way to tell. You basically have to file it.
 
Brian- that was a great write up you did there. Ok so here's my thoughts.

I think it all depends on the rifle use and your abilities. I've done a handful of triggers in various firearms including the AR. If I'm building a standard AR yes I work all the triggers. I've found that I personally don't mind the heavier pull weight if the pull is smooth and crisp and has a decent break. However I also have a Geissele s3g trigger in one of my AR's and I absolutely love it. Is it worth the 230 bucks I payed for it, ehh that's up to you.

The triggers that I have done are nice and so much better than a basic GI trigger but they don't compare to the break on that Geissele. It's truly the nicest trigger I've pulled in an AR.

I think you should try doing the trigger and see what results you get. What's the worst that happens, you learn something and maybe buy a new trigger group.
 
Thanks to everyone for their advice & experience

Sure Shot wv said:
I think you should try doing the trigger and see what results you get. What's the worst that happens, you learn something and maybe buy a new trigger group.
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This is the conclusion I've come to.

I'll put in a few hours working on it & if I'm frustrated I'll spring for the extra cost of a drop in. The next question is which trigger assembly. This rifle is not deluxe enough for a $200+ trigger group. :)

...bug
 
I've always been pleased enough with the Rock River Arms 2-stage match triggers and the CMMG adjustable 2-stage.

I haven't bought a trigger for a couple of years now- but they used to go for $120 each.
 
Going with the Rock River 2 stage would not be a choice you'd regret. Good solid trigger with decent feel, pull weight is around 4.5-5 lbs. Its what RRA is shipping in their NM models.
 
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