M4 mil-spec trigger...

[Sweet Shooter]

So it appears my new SIG M400 has an 8Lb, four-stage trigger. Does anyone opt to live with the mil-spec stock triggers? Can any degree of accuracy be squeezed out of the gun with the stock trigger? Will they improve with age/use?

If not what do you guys recommend I drop in there without filing bankruptcy?
Is there any reason to stone the stock trigger? I've read that is spoils the hardened surface.

-SS-

[CharlieDeltaJuliet]

They will wear a little and get slightly better. A good gunsmith can stone the trigger to get a lighter pull. I recommend the RRA two stage trigger. It is good and cheap(ish). I have my mil-spec lightened to about 2.2lbs. I would not recommend trying it yourself unless you have a replacement to go in it.

[djcantr]

You can try some polishing and JP springs. Some people have to lighten the hammer to use the lighter JP springs. I don't have a trigger pull gauge, but mine is decent considering I just spent $10 on JP springs and invested some time polishing. You might give it a try before spending a bunch of money.

[Eghad]

For $54.00 and about 5-10 minutes to install

ALG QMS Fire control Group & the JP Yellow Springs

[Metal god]

I had a 7 1/2 lbs pull that I got down to 4 1/2 pounds by light stoning ( about 15 or 20 light circles , just enough to feel the burs go away )and buffing till the hamer and trigger were as smooth as glass . I buffed it with a roto-zip and small buffing wheel . It is so smooth it's not even funny .

A quick easy way to reduce the trigger pull is to put in lighter springs http://www.midwayusa.com/product/579...-reduced-power . This may cause lighter hammer srtikes on some mil-surp ammo and failers to fire .

RRA for $120 is a good trigger for the price but I here they do not have a long life . Im not sure what the number is but I'd expect to replace it before you hit 10,000 rounds

This trigger is on sale often at PSA for $180 http://palmettostatearmory.com/index...d-trigger.html and is tested to 25,000 rounds . I think that makes it worth the extra $60 IMO

[Eghad]

The only problem with polishing some triggers is that the surface has the metal hardening on the surface and is not through hardened.If you get too aggressive with the polishing and remove some metal and take the hardening off you will be ordering a new trigger group in the future.

If you are using Mil Surplus or foreign ammo get the Red JP Springs.

[Skadoosh]

Sweet Shooter, since you do not have Private Messaging enabled, I could not PM you.

I have an virtually unused RRA 2-stage NM trigger for sale if you want it. PM me if interested.

See it here: http://thefiringline.com/forums/show...ight=rra+stage

[Eghad]

Nothing personal but isn't $125.00 for a used RRA National match just a tad pricey? I bought mine for $120.00 about 6 months ago brand new. You might have better luck reducing the price.

[Striker1]

Another vote for the ALG-QMS

[Sweet Shooter]

How do I know which pin small or large to order?
I have now enabled Private Messaging... didn't realize it was turned off.
-SS-

[Sweet Shooter]

Here's a thought... if stoning the surface removes a case-hardened layer wouldn't using the trigger then eventually case harden it again? What have the detrimental effect been after stoning? Any experience?

Also has anyone seen that chap who inserts a sear engagement screw in above the pistol grip screw?

-SS-

[RT]

http://www.rainierarms.com/?page=sho...roduct_id=3022

The ALG Defense ALG Combat Trigger (ACT) is designed for those shooters where tradition, value and regulatory concerns are of primary importance. The pull of the ACT is very similar to a standard mil-spec trigger, however it is sharper and the grittiness of the stock trigger pull has been removed while the traditional reliability of a stock trigger remains.

[Eghad]

Don't forget to throw in the Yellow JP Springs in with the ALG for an even better trigger.

It was explained to me that The regular AR-15 triggers are not fully heat treated they are only surface hardened. Once you remove the layer of hardening it is gone. I assume that the surface was hardened to increase the life of the trigger. If you are too aggressive and modify the trigger control group on a semi auto weapon bad things can happen. If these bad things happen the recourse can fall on you.

I wouldn't undertake a trigger job on a weapon unless I was trained to do one properly and understood how the trigger parts were supposed to function and cycle and what the proper contact and angles were. The people that do this know how far they can tread and even then they sometimes make mistakes.

The people that make the fire control groups at ALG understand all this. They provide a drop in product for $45.00 that doesn't require any tampering with that provides a nicer trigger pull than the stock parts.

[madcratebuilder]

Originally Posted by Sweet Shooter

If not what do you guys recommend I drop in there without filing bankruptcy?
Is there any reason to stone the stock trigger? I've read that is spoils the hardened surface.

ArmaLite offers a two stage trigger that I feel is the best bang for the buck going. It's adjustable with a simple spring position change, .5lb increments over 1.5lb range.

The surface hardening on oem triggers is about .008-.012 deep. Aggressive stones well break through this, but you normally don't need to be aggressive. Light stoning to smooth the contact surfaces, a change in spring tension can give you a much improved trigger feel.

It helps to have a trigger fixture to hold the parts for fitting, simple to make, a flat surface with two pins.



There are methods of rehardening the surface, plus there are advanced techniques of modifying the AR FCG. These involve welding, grinding and surface hardening of parts.

For most shooters a drop in replacement is the best bet.

[Sweet Shooter]

Went to a local store and ended up buying a RRA National Match 2 stage. Impulsive but I tried the triggers on a couple of RRA M4's they had there and they felt really nice. 120 bucks.
-SS-

[Dfariswheel]

Here's a thought... if stoning the surface removes a case-hardened layer wouldn't using the trigger then eventually case harden it again? What have the detrimental effect been after stoning? Any experience?


Metal doesn't work like that.
Case hardening is a process that adds carbon to the surface and gives the metal an almost glass hard surface layer while keeping the metal underneath in a softer state so it won't shatter.
Using the trigger can in no way "re-harden" the metal because that can't re-do the hardening process.

Since the metal underneath the case hardened layer is soft, when the metal is stoned and the layer is broken through, this exposes the soft metal.
Being soft, it can't maintain the critical angles and the parts quickly wear.
The wear can cause any number of problems, including a trigger too light and unsafe, a trigger with a heavier, creepy pull, to a trigger that won't stay cocked.
Since the exposed metal is soft, it can't maintain it's shape and the trigger pull will constantly change causing any or all of the above conditions as the metal wears.

[Nathan]

http://www.triggerwork.net/ar15s.html

This guy gets lots of good reviews on AR15.com.

[Sarge]

Dfariswheel nailed it. I've slicked triggers on SA & DA revolvers, numerous auto pistols and about a dozen models of rifles over the last 35 years. The basic AR is one trigger I wont touch for the reasons he stated. Additionally, I'm not aware of an Armorer's School which does NOT recommend against it.

The basic M4gery is what it is. The shoot-ability of the little gun can be improved dramatically by improving the trigger, but it needs to be plug & play and you're going to spend some money doing it.

[djcantr]

Is there a process that can be done at home to reharden the trigger parts?

[Eghad]

Back in the day they would heat the metal till it was red hot put it in a container with crushed coal and then put the red hot steel on the carbon and cover it with more crushed coal. let it cool for a while then reheat it till it is glowing red again and quench it in room temp water. I am sure they have some modern solutions. The question is how much time and money are you going to throw at it when I can spend $54.00 and get a considerable improvement in trigger pull with properly specd parts.

[Sweet Shooter]

Well I just finish fitting the RRA National Match and I have to say it is very slick. I reckon it's breaking about 4 Lbs or maybe a tad more but the take up is pure silk and the break is like snapping a glass rod. Very pleased with it. Wondering what the reports of short life span are about? Is this trigger not case hardened?
-SS-

[Skadoosh]

I know one particular RRA 2-stage NM trigger that is nearing 8K rounds on it and is still consistently and cleanly breaking at 4.5lbs.

[madcratebuilder]

Well I just finish fitting the RRA National Match and I have to say it is very slick. I reckon it's breaking about 4 Lbs or maybe a tad more but the take up is pure silk and the break is like snapping a glass rod. Very pleased with it. Wondering what the reports of short life span are about? Is this trigger not case hardened?

The RRA two stage is surface hardened. I have seen the RRA have wear problems with the dis-connecter. One reason I like the ArmaLite two stage, extra thick disco.

Originally Posted by Sarge

Dfariswheel nailed it. I've slicked triggers on SA & DA revolvers, numerous auto pistols and about a dozen models of rifles over the last 35 years. The basic AR is one trigger I wont touch for the reasons he stated. Additionally, I'm not aware of an Armorer's School which does NOT recommend against it.

The surface hardening on AR FCG's is no different than other fire arms. Armorer's School teach maintenance, you well need a collage level gunsmithing class to learn trigger modification.

Anytime you remove much surface material from a contact surface of trigger/hammer sear you need to address rehardening. Research a product called "kasenit".

[Eghad]

couldn't remember kasenit

http://www.gunreports.com/special_re...eel1750-1.html

[Ridge_Runner_5]

Went to a local store and ended up buying a RRA National Match 2 stage. Impulsive but I tried the triggers on a couple of RRA M4's they had there and they felt really nice. 120 bucks.
-SS-

Good choice! That is what I had on my AR and it was a dream! Short takeup, clean break and light pull compared to the GI trigger.