AR-10 vs AR-15 - Comparison

Binary Triggers: What You Need to Know

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Binary triggers allow you to shoot numerous rounds rapidly. Almost as if shooting with a fully automatic gun. This can be useful in many situations, and more importantly, it can be a lot of fun at the range!

Getting your hands on one is relatively easy in most states. However, it is a serious issue in other states. In this article, I go through everything you need to know about binary triggers and try and answer the main question… is Franklin Armory or Fostech Echo the best?

  • The story behind binary triggers
  • How binary triggers work
  • How to set up binary triggers
  • The purpose of a binary trigger
  • The best binary trigger: Franklin Armory or Fostech Echo?
  • Is a binary trigger worth it?

Trigger Types

Before we delve into binary triggers, there are other forms of gun triggers to know. These are:

  • Single-action Trigger: Fires the round with a single action of releasing the hammer.
  • Double-action Trigger: Fires the round by performing a double action. Cocking and releasing the hammer.
  • Double-action/single-action (DA/SA) trigger: A combination of the double-action and single-action mechanism. During the first action, the trigger both cocks and releases the hammer/striker.
  • Release Trigger: The hammer/striker is released when the shooter releases the trigger rather than pulling it.
  • Binary trigger: Allows the shooter to fire when pulling the trigger and then fire another round when releasing the trigger.

Important note: Not everyone has access to binary triggers. These are banned in parts or the United States. In purchasing a binary trigger, ensure that you check with your local and state authorities to verify that they are legal where you live.

The Story Behind Binary Triggers

Any device or mechanism that increases the fire rate of a firearm are known as bump stocks. In addition, a binary trigger performs the same function. Therefore it is also classified as a bump stock.

Bump stocks help with burst firing. It enables firing rounds one after the other using the recoil of a semi-automatic weapon. You can install bump fire stocks on a variety of standard AR and AK platforms. Depending on the gun, they can fire between 400 to 800 rounds per minute.

Binary Triggers: What You Need to Know Bump stock animation
Bump stock animation, Wikimedia

According to the Gun Control Act of 1968 and the National Firearms Act of 1934, bump stocks and similar devices are classified as “machine guns.” Machine guns enable a shooter to start continuous firing with a single trigger pull. As a result, these devices function as an automated mechanism.

After the 2017 Las Vegas Shooting incident, the U.S. Department of Justice prohibited the use of bump stocks. Furthermore, following the incident, current owners of bump stocks must either destroy or surrender them to the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF). Moreover, those found guilty of possession will face a 10-year jail sentence and a fine of $250,000.

However, on March 25, 2021, the Sixth Circuit Court of Appeals overturned the ban on bump stocks, and soon after, binary triggers became legal in most states.

Binary Triggers Today

Since binary triggers became legal, authorities granted permits to some manufacturers. Brands like Franklin Armory and Fostech Echo began to produce and sell these devices. So if you want to try shooting with binary triggers, you can now easily find them. However, take precautions, especially when ordering online. Sellers first determine if the product is legal in your state. Otherwise, they won’t sell it to you.

How Binary Triggers Work

A binary trigger is a gun attachment mounted to a weapon. This system significantly improves the firing rate of the weapon. It enables you to fire one bullet after one trigger pull. Then immediately firing another round after the trigger is released. Thus, allowing you to fire rounds as if you were using a fully automatic weapon.

Upon pulling the trigger, the sear releases the hammer. When the hammer hits the firing pin, the cartridge in the chamber explodes. After shooting, the bolt then returns to its original position. You can reset it by squeezing the hammer down.

You can add a second sear to the binary trigger to make it work. Besides the disconnector, the second sear captures the hammer upon firing, hence reversing your factory trigger.

In addition, squeezing the trigger keeps the round from firing. So removing it triggers the second sear. This allows the hammer to hit the firing pin again. After firing the second round, it will repeat the process. The YouTube video below shows how a binary trigger works:

The Purpose of a Binary Trigger

Do you want to enhance your shooting experience with your current AR-15? If so, then the binary trigger can make your firing game enjoyable. Using it is an excellent way to enhance your practice drills. Especially, if it’s legal in your state. Why not bring your shooting to the next level?

But before that, there are three modes or trigger operations for the binary trigger. These are listed below.

  • Safe mode: Will not fire
  • Semi-automatic mode: One round per pull
  • Binary mode: Will fire one round per pull and another round on release

Note, the rounds will continue to fire from the gun’s chamber when in binary mode. The gun’s three selector feature allows you to cancel the second round by switching to safe mode or semi-auto.

The BFSIII is ideal for tactical use, recreational sports, and competitions. In addition, the BFSIII offers shortened round split times. It also enables the shooter to take two different shots with a tighter group. Additionally, a variety of AR models, such as the AR-10 and AR-15, are BFSIII-compatible. Thus, it functions without alteration on uppers in 9mm and .22 LR.

Always keep in mind that you have no permission to alter the BFSIII’s internal components. Incorrect installation may lead to getting your warranty void.

Binary Triggers: What You Need to Know Franklin Armory BFSIII 22-C1
Franklin Armory BFSIII 22-C1, image from the official site

How to Set Up a Binary Trigger 

Installation of a binary trigger isn’t the same for all firearms. It usually depends on the gun you’re using. Generally, binary triggers are simple to install. It should take you less than half an hour — including detaching the old trigger and testing.

To set up a binary trigger, first, take out the safety selector and the hammer. Second, detach the old trigger. Third, install the BFSIII. Lastly, replace the safety selector and hammer. Then finally, you’ll be ready to try it out.

Binary Triggers: What You Need to Know Franklin Armory BFSIII-ARC1
Franklin Armory BFSIII-ARC1, image from the
official site

If you don’t know how to set up a binary trigger, I recommend seeking help. Incorrect installation may result in an accident. This may lead to misfires or something much worse.

Which Is Best: Franklin Armory or Fostech Echo?

Franklin Armory and Fostech Echo are both well-known binary trigger distributors. They are both compatible with AR platforms. Furthermore, they have many similarities. First is that their trigger modes are similar. Another is that both brands offer safe semi-auto and binary modes.

In addition, Franklin Armory Binary Trigger is known for its Binary Firing System (BFS). The BFS is a package that includes the trigger, hammer, pins, and related springs. Its trigger can embrace everything you throw at it — even any bolst, recoil springs, and ammunition.

Franklin Armory manufactures triggers for a wide range of weapons. The list includes the HK MP5, Remington ACR, and almost all 9x rifles and bolt carrier group (BCG) weapons. The AR-C1 and 22-C1 are the top favorites in the BFSIII-Binary Firing Systems

On the other hand, Fostech Echo is a company that only makes triggers for AR platforms. The first model came without a bolt carrier. This means that you’ll need a full-auto bolt carrier in your AR platform for it to work properly.

The Fostech trigger is easy to assemble, but there are some aspects to consider. First, attach the lower receiver before pulling the trigger. If you don’t follow this instruction, your parts may scatter. Thus, making the trigger difficult to assemble. Second, try squeezing the small lever on the back of the assembly to begin the installation.

Binary Triggers: What You Need to Know Echo AR-II Trigger
Echo AR-II Trigger, image from the official site

Both Franklin Armory and Fostech have a 4.5- to 5-pound trigger pull. Without any tuning, Fostech is more stable and slower yet works well with piston uppers. Both are exceptional, but Fostech wins on reliability.

Franklin Armory offers less resistance and much more pressure on the release. It’s a good choice if you’re looking for speed.

Is a Binary Trigger Worth it?

When it comes to price, binary triggers generally cost between $300 and $500. So not cheap, and that kind of cash can get you a lot of other accessories as well. Also, unless you practice a lot, an automatic trigger can be more of a drawback than a benefit in a home defense scenario.

Now saying that, if you do have the extra cash, then it’s worth a try. Why you may ask? Because it is fun!

Tell me about your thoughts and experience with the binary triggers in the comment section below.

Want to read more about triggers?

1 comment
  1. Surely there is has to be an easy way to make an AR-15 homemade or diy Binary trigger for way less money especially for a poor such as myself. $300-$500 seems like a bit on the Holy Crap expensive trigger for all that they are. you can buy a complete firearms for that price in some instances even build an AR-15 for that much money . if anybody know of a way to modify a trigger to shoot binary I would appreciate the info? Oh and to let you know, no I am not affiliated with any type of law enforcement, I am just a plan and simple hillbilly with more time then money simply put poor and broke. thank you and God Bless

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