Thomas Allen Graves is an engineer from Texas who has numerous patented inventions in a variety of fields including firearms and ammunition. In this article, we’ll take a look at a pistol caliber carbine designed by Mr. Graves called G1 Combat. Developed in 2014-2015, the Graves G1 Combat has several interesting patented design solutions such as its mechanism of operation which is described by the designer as a multi-staged blow-back with 3-cycle, 2-stroke gas damping. Let’s take a closer look.
Pistol Caliber Carbines @ TFB:
Graves G1 Combat is chambered in 9X19mm Luger or 7.62x25mm Tokarev. The gun features an inline barrel/stock layout and a one-piece upper receiver and stock. There are three safeties built into this PCC: a grip safety that locks the trigger, firing pin and disconnector, a manual safety that locks the bolt and trigger, and a receiver latch safety that prevents an accidental discharge during disassembly. The overall length of the Graves G1 Combat carbine is 35.75″ (with a 16.25″ barrel) and it weighs about 6-7.3 lbs. These were some of the regular specs and features of the gun, now let’s take a look at its unique design elements.
There are two main patented technologies used in the design of the Graves G1 Combat carbine called FLEX-FIRE and CAPTIVE PULSE as well as an ammunition-related technology called ROCKET FIRE which is not a part of the system per se but is marketed with the gun. To avoid misinterpretation, I’ll quote the description of each invention from Mr. Graves’ website and then sum up the way I understood these technologies after discussing them with him.
FLEX FIRE
FLEX FIRE® fire control technology can provide a simple and durable trigger reset mechanism that may use rigid contact between a trigger, and a gun bolt, or slide arrangement during the earliest part of an operating cycle, and the trigger may be blocked from depression by the gun bolt, or slide up to a complete operating cycle. This system may automatically reset the trigger during each gun bolt, or slide cycle independent of trigger “pull weight”, and “length of pull”. The fire control technology may be applied to pivoting, or linear trigger types with striker, or hammer fired ignitions. This fire control technology is also adaptable to all reciprocating gun bolt, or slide assemblies, including bolt action assemblies, and revolver action assemblies.
Note the bolt and trigger interaction.
This is basically a powered trigger reset similar to what’s used in some AR triggers where the bolt forces the trigger to reset even if it’s still being pulled back. A trigger like this resets as fast as the action cycles providing a full-auto-like rate of fire in a semi-auto firearm while still remaining safe without a risk of an out-of-battery discharge.
CAPTIVE PULSE
CAPTIVE PULSE damper technology may provide a durable and highly effective means for a double acting gas damper, even within a coiled helical spring of a gun bolt, or slide arrangement. The damper may include active heat energy rejection by cylinder volume displacement during 50% of a damper’s operating cycle. The damper can remove energy from a gun bolt’s rearward movement and reject the energy from the system without adding it to the gun bolt’s forward movement. These dampers may be either encased, captive, or remote. They may be used to reduce gun bolt, or slide speed independent of recoil spring energy during both halves of a cycle. They can be used to distribute and reduce recoil, to regulate cyclic rates, to lower thermal, and acoustic signatures, to extend firearm lifespan, to improve feeding systems, and more.
The damper/buffer system of Captive Pulse technology
Essentially, this is a pneumatic system that resists the bolt’s rearward motion. This is what the designer refers to as 3-cycle, 2-stroke gas damping. It’s not just a buffer and return spring assembly but a crucial part of the action without which it wouldn’t work. This technology is claimed to provide smoother and more controlled cycling of the action as well as increase the overall reliability of the firearm and the lifespan of the action parts.
ROCKET FIRE
ROCKET-FIRE ammunitions are gun chamber, or cartridge case based solid fuel rocket motor technology that may be used in combination with firearm ignition systems and gun propellants to accelerate projectiles from gun chambers, and cartridge cases within corresponding gun chambers. Generally pressure is reduced in an expansive rocket nozzle and converted to velocity which is available to do work in inertial momentum. This work may accelerate a projectile to higher velocities than otherwise possible for any given unit of propellant. The ammunitions technology may be applied to all scales of application from small arms to artillery, and cannon systems.
Cutaway 3D model of a cartridge with a Rocket Fire case design
As seen in the picture above, a cartridge case built with the Rocket Fire technology is like internally bottlenecked. This design allows for reducing the propellant consumption or achieving higher muzzle velocities at a given amount of propellant and dimensions of a straight-walled cartridge case.
The Graves G1 Combat carbine is still in the prototype stage, hence the white look. A couple of changes I’d suggest would be ditching the fixed front sight and carry handle in favor of a top Picatinny rail, adding M-LOK slots on the handguard, using a 1913 rail for stock attachment, making the gun AR-15 pistol grip compatible (unless there is a mechanism inside the grip) and yes, making it take Glock mags. These are sort of industry-standard features and would just make the gun more customizable and accessory-friendly.
For more information visit Mr. Graves’ website: www.thomasallengraves.com. To learn more about the design of the Graves G1 Combat carbine, you can read the US patents protecting it via the following links: US9568264, US9816772, US9939221, and US10502511.
Pictures by Thomas Allen Graves, www.thomasallengraves.com