January 30th, 2024
Triggers for AR-Platform Rifles — Single-Stage & Double-Stage
AR-platform rifles are fun and versatile, but the standard, mil-spec triggers leave much to be desired. They tend to be gritty, with creep and heavy pull weight. One of the easiest, most effective AR upgrades is a trigger group swap. An improved fire control group makes a huge difference. There are many aftermarket trigger options for the AR platform rifles. Choose single-stage or two-stage, either standard trigger assembly or unitized “drop-in” trigger, such as those made by Timney or Triggertech.
When upgraded with a precision trigger and match barrel, AR-platform rigs work great in NRA High Power competitions (Photo from NRA Blog, at Camp Perry).
Two-Stage vs. Single-Stage Triggers
Two-stage triggers have two separate movements. The first stage offers a light, spring-loaded pressure that works against the shooter’s pull until stopping at the second stage – this is called “take-up”. If there is no spring pressure, it is known as “slack”. Should the shooter continue to pull the trigger once he’s arrived at the second stage, the mechanism will operate like a single-stage trigger from there until engaging the sear and firing the gun. Some shooters prefer a two-stage trigger because it allows a mental preparation (first stage) before the final decision to “break the shot”.
Single-stage triggers feature no take-up or slack, as they begin engaging the sear as soon as the shooter begins pulling the trigger. Some competitive shooters prefer the two-stage trigger because of the feedback it provides during its first stage, while other shooters, including those using their rifle in tactical scenarios, may want the surety of a single-stage trigger, ready to engage and fire once their finger is inside the trigger guard. Regardless of preference, a good trigger will feature minimal creep and should be free of grittiness, providing a smooth, even break.
Drop-In Trigger Assembly vs. Standard Trigger Group
Once you decide between a single-stage or two-stage trigger, you can choose between standard and drop-in trigger groups. Standard trigger groups feature all the fire control group parts separated, and need to be pieced together and installed much like a mil-spec trigger, while drop-in trigger are pre-assembled and contained within a casing that simply drops in to the receiver and accepts the pins, hence the name.
After-Market Trigger Comparison
Some shooters prefer drop-in triggers due to the ease of installation, while others opt for standard groups so they can access the components individually for cleaning adjustment or replacement. If one piece of a drop-in trigger fails, you’ll need to either replace the entire unit or send it to the manufacturer for repair, whereas you may be able to simply replace the broken component of a standard trigger without needing a whole new trigger set.
Trigger Terminology — “Creep”, “Stacking”, “Overtravel”
“Creep” or “travel” is the distance the trigger moves between the end of take-up and when the trigger breaks to fire the fun. Too much creep can affect accuracy, but no creep can be unsafe, as the shooter may not be prepared to fire. “Stacking” occurs when the trigger weight actually increases during travel — this shouldn’t happen. Lastly, “overtravel” is the distance the trigger continues moving back after the gun fires.
This article is based on a longer story in the NRA Blog.