The Advanced Combat Trigger, or ACT, from ALG Defense is probably as far as you can take a mil-spec trigger and still be considered ‘mil-spec’.
Before we get into the details of mil-spec, and perhaps bore you to death, I’d place the ACT at the pinnacle of performance of ‘mil-spec’ triggers. There isn’t much more you could do to a ‘mil-spec’ trigger before it would no longer be ‘mil-spec’.
For those who aren’t familiar with the term ‘mil-spec’ it basically means a set, or rather range, of specifications in which something must fall in order for it to be considered within ‘Military Specifications’. ‘Mil-spec’ doesn’t necessarily mean quality or improved function, it simply means the item falls inside of the allowable specifications. The main purpose of ‘mil-spec’ is to make an armorers job easier, they should be able to swap out any mil-spec part from one from company with the same part from another company and it will still function. This is a huge benefit in the field when getting rifles (or any other item) functional again may mean the difference between life and death.
The simplest way to illustrate what mil-spec is, that anyone can not just understand but also feel, would be trigger weight. In order for a standard M16 (or AR15) trigger to be considered ‘mil-spec’, the pull weight must fall between 5.5 and 9.5 pounds. That’s not a type-o, the allowable variance is 4 pounds.
There are other factors that are involved as well, of course, right down
to the diameter of trigger pins but the point is, not everything
‘mil-spec’ is the same when it comes to quality, it simply means “this
part will fit and work”.
Why then would the average person even care about getting a mil-spec trigger, why not get something else? Cost could be one issue, the original mil-spec trigger was designed to be mass produced very inexpensively and with simple machinery. Going with a top of the line mil spec trigger is still going to be significantly less expensive than more refined trigger, such as those offered by Geissele Automatics.
The other side of the coin will see many police officers and other government agents, if they choose to use their own AR15 as a patrol rifle, be required to have rifles or carbines that are “mil spec” and as such, they need to have something that falls into those specifications.
When it comes to ACT, ALG Defense uses hard lubing and has polished every interface surface. They use different metals as well, 8620 alloy steel for the trigger and hammer as well as 1070 high carbon steel for the disconnected and 4140 chromemoly for their pins.
The ACT also comes with two different springs, a tan spring which is 6.0 pounds to maintain ‘mil-spec’ compliance and a purple spring which will drop the pull weight down to 4.5 pounds for use when a higher pull weight isn’t required.
The pull on the ACT is a smooth, consistent pull and leads up to a clean break. There is no grit or creep, nor is there a shelf. Reset is relatively short, positive and both audible and tactile.
We’ve ran the ACT in our 9mm Quarter Circle 10 pistol builders kit for the past two months and with over 1,000 rounds downrange, the ACT was an excellent choice for this build. 9mm builds can be picky on the types of triggers that will function properly in them and there hasn’t been a single hiccup with this setup.
There will be a full video up on this build in the next week or two, until then you can check out our on video the ACT–