From the ‘60s Vietnam War M16 to the current M4, there was a continuing need to update standard gas impingement AR-15 with improved aftermarket parts. Although radical and “space age” in appearance for the time, the Black rifle has trigger/hammer group that draws its origin from the venerable M1 Garand rifle, and even further. In fact, the firing group traces its roots back to the early 1900s, applying the Browning design of his great Auto-5 semi-automatic shotgun.
While the AR15 modifications could include a free-floating barrel or rifle compensators, an alternative trigger group will have an immediate and advanced result on rifle`s accuracy since the trigger is the key interface between the shooter and gun. As it is known, the original AR-15 fire control system was designed as a military weapon system resistant to dirt and junk at the price of loosening the consistency; and it is precisely, the consistency that offers accuracy from shot to shot. Since the AR15 service’s trigger violates that basic principle of accuracy, it is more rule than exception that best AR-15 triggers rarely come on off-the-shelf rifles. As every conservative and rigid part of society, the Army philosophy is that one had to adapt himself to the weapon and not the other way around. Fortunately, the shooting public has a ton of aftermarket options to find an enhancement for their AR15s, and among other things, it is a replacement trigger. As the most popular center-fire rifle in America, a legal semi-automatic form of the AR15 gives the owner an easy customization platform with numerous advanced triggers available. Utilizing upgraded triggers can be a noticeable improvement over the stock triggers that typically come with these types of guns.
The most important rule in marksmanship is that the best triggers will "break" without any warning, in that way increasing accuracy because shooter cannot flinch to anticipate the recoil of the shot. Accordingly, the triggers could be classified on two main categories: on single stage and two-stage as well on Mil-spec and drop-in triggers. Within these categories, there is a huge variety of material selection, weights, and trigger bows. While the single stage triggers are, the most common type found in the AR15 platform they could be heavy and mushy because they were originally designed for military weapons with the primary concern being safety. Nevertheless, those combat-style triggers are a robust, proven and non-adjustable and due to their quick operation and reliable design, most gunmen are well served by those mil-spec triggers.
As a result, the majority of bolt-action and service rifles sold on the civilian market come supplied with a basic single stage trigger. In other words, traditional hunting and precision rifles in the bolt gun world utilize a single stage trigger due to its crisp/light trigger pull (4 lbs. or less), enabling an experienced rifleman to shoot slightly faster with a single stage trigger. However, the Army believed that a light pull was seemed too dangerous for a combat rifle, so the pull weight was increased to a range of 5.5 to 8.5 lbs., and while the AR15 single stage trigger was designed to operate safely, the precision was put in a second plan.
On the other side, the aftermarket AR15 triggers can usually be adjusted for trigger pull weight, the length of travel, or any number of other advanced features. The best single-stage AR15 triggers will give you a lighter trigger pull with less accurate but faster follow-up shots ideal for some competition and hunting. Undoubtedly, the modern trigger upgrades are departure from the standard AR-style fire control group offering a drop-in trigger unit placed in their housing dropped into the lower receiver and held in place by the hammer pin and trigger pin.
Actually, the majority of drop-in triggers are built as the single-stage version. The trigger pull quality of the most drop-in units is superb and an radical improvement from Mil-Spec/parts kit. The simplicity of drop-in module means that just about anyone can easily install a brand new, specialized trigger and second, the trigger, sear, hammer, and spring are all encased in an aluminum housing frequently called a cassette.
The second types are 2-stage drop in triggers with two separate stages. In the first stage, the trigger comes back a bit, and a distinctly increased resistance, followed in the second stage by the actual surprise break trigger-pull that will fire the rifle, follows the action. Since the trigger weight is divided between the two different portions of the trigger pull, it has lower perceived pull weight when compared to a single stage trigger. Consequently, a two-stage match trigger might work great for many precision shooters because it enables them to begin applying light pressure to the trigger in order to "prep" or "stage it." As a second stage, the shooter is waiting for sight picture to settle and simply apply just a tad more pressure and fire the weapon.
The triggers are a hugely personal preference, but until recently, they were an expensive custom operation, what is fortunately changed particularly due to modern manufacturing methods and competitive-shooter-owned companies such as Geissele Automatics or Timney Triggers.
When modifying the AR15 trigger, the owner should carefully consider what type of shooting he intends to do the most. The top-end AR15 fire control group will be more ergonomic and comfortable for the shooter featuring a smoother, lighter and more accurate trigger.