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.