TFB REVIEW: Franklin Armory B&T BFSIII Binary Trigger

by Pete

Anyone with even a passing knowledge of my work here at TFB knows my love for the Swiss-made guns of B&T. The APC9, the company’s flagship law enforcement and military submachine gun/pistol caliber carbine is refined, capable and a true pleasure to shoot. So as excited as I was to try out Franklin Armory’s latest binary trigger, the BFSIII B&T-C1, the thought of altering one of my favorite firearms made me a bit queasy. But in the name of science, I set forth to tap pins and… well that’s all it really takes to install the Franklin Armory BFSIII binary trigger in the B&T APC9.

Before we begin:

  • In my conversations with B&T USA, they mentioned that many owners have called them to ask if the new Franklin trigger will fit in certain APC guns. B&T does not test any aftermarket triggers. Installation advice and compatibility questions should be directed to Franklin Armory.
  • In addition, this review is specific to the APC9, but I know that our own Rusty S. also has the new binary trigger en route for his APC45 and will be updating us as soon as he can get some trigger time. Now if we can convince Richard L. to test the B&T-C1 in his GHM9 we’d have all our Swiss PCC bases covered – minus the TP9.
  • Professional installation of the BFSIII B&T-C1 is recommended. Most likely this is a liability concern since this trigger drops in nearly as easily as an AR trigger. Franklin Armory does offer an installation service if needed.
  • I have only had the new trigger for a few weeks and a few hundred rounds – so take that into account as you continue reading. My intent was to do a basic installation how-to and function check  this go-around – then I’ll post a follow-up review in a few weeks with higher round counts.

Let’s take this review in reverse…

The Franklin Armory BFSIII binary trigger for the B&T APC line of pistol caliber carbines works, and it works really well. Much like their H&K binary triggers, it takes some practice to get the pull-release cadence down to a science. But it didn’t take me long to simulate fully automatic fire in short bursts. Let’s take a look at a brief demonstration video.

All that smoke is the result of overfilling the SilencerCo Omega 9K with too much Suppressor Foam from Inland Manufacturing. Just squint your eyes and imagine that you are at a Pink Floyd laser show in Bern.

Surprisingly, the APC9 in binary mode is easier to control and operate when shooting offhand rather than off the tripod. And I think the B&T binary trigger is slightly easier to master than the H&K version.

Still, the B&T C-1 is a lot of fun – with the right finger cadence the BFSIII binary trigger gives the APC9 a simulated two round burst at worst and a slightly reduced rate of fire simulated full automatic at best. If you don’t grin after pulling the Franklin trigger in your B&T, you just might be dead inside.

TFB REVIEW: Franklin Armory BFSIII Binary Trigger B&T-C1 APC9

I mentioned that I was reluctant to blend Swiss precision with American ingenuity, right? B&T USA was kind enough to allow me to buy a spare APC lower receiver for testing. Please don’t badger my friends in Tampa – they don’t stock APC lowers for retail sales at this time. Besides, after going through the installation process twice, it takes less than five minutes to swap triggers.

Writer’s Note: My secondary lower is missing a few parts due to commercial availability. Specifically, the bolt release and takedown pins. At times I also use AR15 trigger and hammer pins which are shorter than the APC pins – I wanted to be able to compare the stock trigger to the Franklin binary trigger. Follow the installation instructions and use B&T parts where required. Don’t forget to follow all the rules of gun safety.

Note: The bolt release does not need to be removed to install the Franklin trigger

The B&T-C1 Trigger comes neatly packaged with all the required parts, including selector marking stickers for the receiver. The binary selector markings are an important safety requirement for binary trigger installations. Without the markings, shooters could unknowingly rotate the selector past fire to binary mode, creating a potentially dangerous situation. Follow the instructions and use the stickers.

From Left to Right: B&T hammer and spring, the B&T Trigger and spring, binary selector unit, trigger pin spacer(s) and Franklin stainless safety detent

Speaking of instructions, I found the included page of how-to materials to be a bit lacking. I prefer step by step pictorial instructions when dealing with unfamiliar platforms. However, the install should be an easy journey for those that have swapped AR triggers in the past. (If the job is available, I volunteer to be Franklin’s new technical writer.)

The first step is to remove the stock selector by pushing in on the small hole in the center. The selector switch is then free to slide up and off the rest of the selector assembly. Be careful: the retaining pin and spring can launch into low earth orbit pretty easily.

Set the right side selector assembly aside. The parts are required to return the APC back to its stock configuration.

Directly below the fire control/safety selector axle in the APC receiver are two spring-loaded detents that keep pressure on the safety selector. You may have to apply a small amount of pressure on each of the detents to get the selector out of the receiver.

As for the replacement of the stock fire control parts with the BFSIII Binary Trigger, it’s a simple process of tapping out pins from right to left, removing the stock trigger and hammer and then installing the Franklin Armory trigger using the slave pins and spacers to keep everything in line while the stock pins are retapped in from the right.

Stock trigger and selector on the left compared to the Franklin Armory triggers on the right. The new stainless safety detent and one stock detent spring gets installed on the left (pictured right) of the receiver. Remove the left side selector lever using the included hex wrench then insert the selector axle through the selector hole in the receiver. You may need to press down on the detent to get the shaft fully seated. That’s what she said…

That’s it, follow field disassembly/reassembly procedures, we helped you out here.

Note: Without the proper fire control parts, I used AR15 pins to hold the trigger in place. This was for a visual comparison only - use proper B&T parts when swapping to the Franklin trigger.

Conclusions: The Franklin Armory BFSIII Binary Trigger for B&T

Although the Franklin Armory trigger comes in at more than twice the cost of a typical drop in match trigger, APC owners with the right budget will have a blast simulating fully automatic fire on the range. In semiautomatic mode, the pull weight and break feel just as good as a stock. With practice, it’s possible to unload the fifty round mag from F5 Manufacturing in less than 10 seconds.

Given the opportunity, I’ll be purchasing the B&T binary trigger from Franklin Armory. Next up will be a comparison of the Geissele APC trigger in semiautomatic versus the stock and Franklin APC triggers.


Works with APC9 & APC45 & GHM9

The BFSIII™ for B&T is a 3-Position Trigger. In position 3 it will fire 1 round on Pull and 1 round on Release. This makes it the fastest semi-automatic trigger on the market. The BFSIII™ is ideal for Tactical and Competition use. The BFSIII™ provides greatly reduced split times between rounds and the ability to place two separate shots into a tighter group.

Some B&T firearms may require slight modifications to the interior of the lower plastic to properly fit our trigger. The modification is still reverse compatible with the OEM trigger.

Trigger Operation:

Position 1 – Safe – Will not fire.

Position 2 – Semi – Fires 1 round per pull.

Position 3 – Binary – Fires 1 round on pull and 1 round on release.

  • Ambidextrous Safety Selector.
  • Some firearms may require additional fitting
  • MSRP $499.99 


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2 of 12 comments
  • Ryfyle Ryfyle on Jun 25, 2018

    Really completes the B&T. Which looks like the kind of weapon that demands the ability to spray lead. Make sure to get some stronger recoil springs for that.

  • Space Man Space Man on Jul 09, 2018

    Where could one find a spare safety lever retaining pin spring if it went into orbit before reading this?