What’s the deal with two-stage triggers? I was looking at one of the self-defense ARs you recommended, and one of the extra cost options was a two-stage trigger. What is it and why would it be be desirable?
First things first, go read up on trigger terminology real quick (here’s an old Ask Foghorn article about that subject). Now that we’ve got the nuts and bolts under our belt, let’s talk a little about the applications for the different types of triggers.
As you know, there are two main types of triggers; single stage triggers and two stage triggers.
In the beginning, there was only the single stage trigger. You pull the trigger, the thing goes off, and then reload. The guns weren’t very accurate anyway, so having a good trigger didn’t make much of a difference. All you needed was something that tripped the mechanism and made the gun go bang.
That all changed as guns started getting more accurate. While a gritty eight pound single action trigger pull would be fine for a 1780′s era military musket, the same trigger on a finely crafted Kentucky long rifle would be terrible.
The reason crappy single stage triggers suck for precision work is that the heavier the trigger is, the more force is required to move it by the shooter. As the shooter applies force to the blade of the trigger, the tendency is for the muscles in his hand to contract and move the firearm off target. With precision shooting, the barrel needs to be exactly aligned with the target, and any deviation even by a single degree can throw the round completely off target. Precision shooters needed something better.
The obvious solution was to lighten the existing single stage trigger, and many still feel this is the best solution. I’ve fired a number of modern firearms where I felt like a strong enough breeze could set the gun off, let alone the pressure of my finger (the Barrett MRAD is one of those guns). Which is fine if you’re on a flat range, but if you’re hunting or “in the field” and expect to be moving around with a loaded gun, a hair trigger may not be the safest thing.
The next best solution someone though up was the set trigger which was a compromise between the gritty, crappy single stage trigger of old and the new super light (unsafe) triggers. With a set trigger, the user can mechanically switch from the safer trigger to the lighter trigger when they need to take a precision shot.
The issue is the set trigger still requires the shooter to do something before taking the shot, which can be a bit of a bother if you’re pressed for time. The solution is to give the trigger the safety of a heavier overall pull with the accuracy of a lighter break. Thus, the two stage trigger.
You can imagine a two stage trigger like a gentle hill with a low brick wall at the top and a steep drop on the other side of the wall. A single stage trigger is more like a gigantic wall on a flat plane with the same steep drop on the other side. The tops of both of the walls are level with each other and just as high. The difference is that with the two stage trigger, the shooter only needs to apply a hair more effort to get over that wall having already done the prep work (walking up the gently sloping hill).
That’s where the two stage trigger gets is power. The overall force required to release the firing mechanism is the same in both, but with the two stage trigger you can “prep” the trigger by taking up the slack (walking up the hill and stopping just before the wall), and then once you see your opportunity to take the shot, you only need a hair more pressure to get the job done. Or drop over the wall. Or whatever metaphor I’m using now.
The point is, the final amount of pressure required is much less than with the single stage trigger and greatly reduces the sympathetic muscle contractions that can throw your shot off.
But that’s not where the wonder of the two stage trigger ends. In a competition setting (where I’m most at home) you often need to take multiple close range shots before moving off to some long range work. Sure, a single stage trigger gets the job done but a two stage trigger gives the shooter the option of using that lighter trigger pull if they need it.
When firing fast, a two stage trigger will work and feel just like an okay (milspec) single stage trigger. But if you want to take a more precise shot, all you need to do is slow down for a second and go back to “prepping” the trigger (by taking up the slack) before you fire.
That’s the reason a two stage trigger is recommended in my self defense builds. If there’s a bad guy coming at you from five feet away the trigger isn’t really going to matter much so long as it works – a single stage will work just as well as a two stage trigger.
But if I’m using a rifle for self defense then either (a) something has gone terribly wrong with my handgun or (b) the baddies are far away. And rather than spraying hot lead over their heads and praying that I hit them, I’d like the ability to take a single precise shot and end the situation. And that’s something a two stage trigger does really well.
So, in short, I like two stage triggers for long distance work. It could have something to do with the NRA HP service rifle competitions I’m fond of (as they only allow two stage triggers on the guns) but it’s my preference. And if I need to take a precision shot that’s the trigger style I prefer.