PLEASE READ BEFORE ORDERING- This specific TRIAD kit only works with the Brownells BRN-180 bufferless upper receivers. If you have any other brand of receiver, you will need to get the correct TRIAD kit for that receiver. While the core chassis is the same in all kits, some of the additional components such as buffers and takedown lugs are specific to the upper being used.
Before ordering your TRIAD chassis, please read over our detailed TRIAD INFO FAQ page. This page lists all specs, and answers all of the "how's and why's". It is important to understand the details of each configuration, as well as the legalities, before purchasing your TRIAD pistol or rifle chassis and/or accompanying parts.
The TRIAD is a Modular Bullpup Chassis, designed to house a standard Mil-spec AR receiver. It also uses a bufferless upper receiver. Once the Mil-spec receiver is installed, the upper receiver simply quick-pins in place just like a standard AR.
Why a Bullpup? Bullpups relocate the trigger and grip forward, greatly reducing the weapon's overall length without reducing the barrel length. This allows a bullpup to be more maneuverable and concealed more easily than a conventional weapon with a similar barrel length. The other main benefit is that it puts the center of mass closer to the shooter's core. This allows more control of the weapon, and much better balance. And if those weren't enough perks, Bullpups also have less muzzle rise, because the recoil impulse is transmitted more directly into the shooter's shoulder. This occurs because the action of the firearm is much closer to the butt plate than on conventional firearms.
One of the main benefits the TRIAD has over other Bullpup designs is the ability to swap barrel lengths and calibers in seconds with a simple upper swap (just like an AR). For example, the user could have 2 different uppers - a 10.5" 300 BLK upper with an optic, and a 16" 5.56 x 45 upper with a scope. The optics remain sighted on both uppers, and the user can swap between the two in less than a minute. There is no limit to this. During testing, we had 6 different uppers of various calibers and barrel lengths that we swapped back and forth. All were complete with optics already sighted in. By changing uppers and magazines in less than a minute, we can swap between 4 different calibers - 5.56x45, 7.62x39, 300BLK, and 9mm.
NOTE: Each brand of upper requires a specific TRIAD kit. While the core chassis is the same in all kits, some of the additional components such as buffers and takedown lugs will be different per kit. We bundle the necessary components in the appropriate kits. If you plan to use multiple uppers, don't worry, we also sell the individual items that make the kits specific. This will allow you to use various uppers on the same TRIAD chassis. These separate parts, plus TRIAD accessories are available HERE.
WHAT COMES IN THE KIT AND HOW DOES IT WORK? The TRIAD chassis ships as a partially assembled lower chassis. The front trigger and selector will already be installed, adjusted, and tested for proper operation. The customer removes the left rear part of the chassis and installs a bare Mil-spec AR lower receiver w/trigger. Once the linkage is adjusted to the trigger, the chassis half is re-installed. If a pistol chassis was chosen, a rear buffer plug, spacer and buffer cap is then installed. If a rifle chassis is chosen, a rear buffer plug, lower butt-plate mount, and buttplate/buttpad is then installed. Rifle chassis also comes with rubber cheek riser, and a 1.5" Butt-pad spacer. NOTE: the pistol chassis can accept our butt-plate, if the customer chooses to upgrade at a later time. Buttplate kits are available on our TRIAD PARTS page HERE.
WHAT ELSE DO I NEED TO MAKE A COMPLETE TRIAD FIREARM? You will need a Mil-spec AR lower receiver, an AR bolt catch (with spring, plunger, and pin), and a BRN-180 upper receiver of your choice. Everything else is provided in the kit.
Below is a breakdown of the kit components:
- 6061 aluminum front trigger housing/receiver
- 17-4 stainless MIM front trigger with QPQ coating
- 4140 steel Anti-walk trigger pins x 3
- A3 Tactical ambi selector with detent spring and detent
- 17-4 stainless front trigger linkage with QPQ coating
- 7075 aluminum transfer bar and rear linkage, bushed with 841 oil-embedded bronze bushings
- Acetal Delrin guide and trigger actuator
- 30% fiber-reinforced injection-molded Zytel polymer main chassis housing
- 4140 steel and 7075 aluminum threaded chassis inserts
- 6061 rear threaded buffer adapter
- 6061 rear butt-plate (rifle chassis only)
- 30% fiber-reinforced injection molded 1.50" extended butt-plate (rifle only)
- Injection-molded elastomer butt-pad and cheek rest (rifle only)
- 4140 quick-disconnect (QD) sockets x 2 on rifle, 3 with pistol
- 4140 steel mag release
- 7075 extended right-side mag release button
- 7075 left-side mag release lever
- Injection-molded Zytel polymer front trigger housing cap,
- 30% fiber-reinforced injection-molded Zytel polymer rear butt-plate support
- Injection-molded Zytel polymer rear cap w/4140 quick-disconnect sling socket (pistol only)
- 4140 ball detent takedown pins x 3
- A3T XENO-patterned reduced angle polymer grip - 30% fiber-reinforced Zytel
- Rise Armament RAVE 140 drop-in trigger