ALG Defense Quality Mil-Spec Trigger (QMS)

Stock Status:

1. Performance Advantages for the Shooter
The ALG Defense QMS trigger pull is smoother than a stock trigger. This is accomplished by honing the sear surfaces smooth while not removing metal below the valleys of the stock surface finish.
Sear geometry has not been changed from standard so the high reliability that the stock trigger is known for is unchanged.
Trigger and hammer are made from true 8620 alloy steel military specification castings, correctly carburized, quenched and tempered for high surface hardness.
Disconnector is 1070 High Carbon steel properly Austempered into the spring range of hardness
Springs are corrosion resistant and meet military specifications.
A full force hammer spring is used for positive ignition of all type of ammunition.
Trigger and hammer pins are improved over stock mild steel by using 4140 Chrome-Moly steel that has been quenched and tempered. Pins are centerless ground to a fine finish and a diameter 0.001 larger than stock to reduce play in the trigger assembly while retaining a slip fit into the weapon lower receiver.
Pull weight is above the U.S. Military minimum pull weight of 5.5lbs but does not reach near the upper limit of 9.5lbs. Generally, the pull weight is about 6.5lbs.

2. Advantages for the Armorer
The ALG Defense QMS trigger is an enhanced standard trigger so maintenance and installation procedures are unchanged.
There is spare parts commonality between the QMS and stock triggers
Trigger assembly parts may be interchanged between triggers, there are no matched sets.
Since it is a trigger meeting the U.S. Military trigger specifications for the M4 Carbine, the ALG Defense QMS can be substituted for lower performing stock triggers while still staying in compliance with Unit or Departmental requirements.


***This product contains chemicals/materials known to the State of California to cause cancer and other reproductive harm. To learn more, visit***

35 Reviews

  • 5

    good quality

  • 5
    ALG Defense Quality Mil-Spec Trigger

    Everything I expected from reading various reviews.....very nice upgrade.
    Extremely fast shipping by BCM. Overall experience A+

  • 5
    Mil-Spec Plus

    This trigger is a step up from mil-spec. Smoother with shorter uptake. Very nice and well worth it.

  • 5
    Quality Indeed

    I bought this trigger kit not needing anything more than an inexpensive FCS option for yet another AR-15 build, but I was not expecting this. The lack of play and crisp break of this trigger is amazing. I do not have any anti-walk pins or anything special. Installed to a JT-15 lower with the supplied trigger pins and the fit is just remarkable. ZERO side to side movement, no "take up" before that defined glass -like break. I picked up some lube as this did not come with any, but I really don't feel that's a star off. For the price and what you are getting, you can't go wrong.

  • 5
    ALG defense trigger

    Love the trigger, have bought a couple of them through BCM. They always ship the product fast and I've always gotten what I ordered with no problems.

  • 5
    Never lets me down

    Trigger assembly works flawlessly! Reliable upgrade.

  • 5
    Great trigger.

    Easy to install, very smooth, and much better than a factory trigger.

  • 5
    ALG Defense Trigger Excellent Choice

    Good quality, great price, easy install. Took to the range and fired both pricey and cheap 300 Blackout ammo with this trigger. Worked 100 over 100....what's not to like. I'll probably buy again for my next build. Good job BCM for getting it in your inventory, processed, shipped, and delivered quickly.

  • 5
    Excellent Quality

    I could not be happier! Excellent quality and a great compliment to my A2 clone.