A Brief History of the One Rifle


History of the “One Rifle” begins in 1920 with US Patent 1,348,702, and coincidentally ends a century later with FoldAR leaping far beyond the One Rifle concept to create the “One Rifle to Rule Them All”. This timeline story explores the history of numerous attempts made over the last century to design and build the “One Rifle”, and how those attempts instead led to “One Rifle to Rule Them All” against all odds and in the face of adversity.

  • One Rifle

    An extraordinary rifle designed to accomplish multiple configurations of calibers and barrel lengths without compromising any areas of performance, reliability, safety or accuracy.

  • One Rifle to Rule Them All

    An exceedingly extraordinary rifle, having all the advantages of the One Rifle, but also includes the ability to conceal inside an EDC backpack while remaining fully assembled, and be deployed within seconds.



US Patent 1,348,702 – Barrel mounting means, e.g. releasable mountings for replaceable barrels using interlocking means, e.g. by sliding pins. [Not a One Rifle.]


Winchester – US Patent 2,100,410 – Features and mechanisms and methods for assembling and disassembling a firearm. Modular weapon family concepts. Articulation and collapsing of firearms for the purpose of storage or transport.


US Patent 2,115,861 – Barrel mounting means, e.g. releasable mountings for replaceable barrels using partial or interrupted threads. [Not a One Rifle.]


US Patent 2,625,766 – Quick Change Barrel. [Not a One Rifle.]


Colt Industries – US Patent 3,756,119 – Machine gun with an automatically engageable, self aligning barrel and receiver latch construction. [Not a One Rifle.]


Baretta – US Patent 4,388,773 – Lever type closing device for blocking and unblocking the barrel of automatic, portable firearms. [Not a One Rifle.]


Mauser – US Patent 4,742,757 – Locking device for a gun barrel of an automatic weapon. [Not a One Rifle.]


US Patent 4,920,679 – Firearm with detachable barrel. [Not a One Rifle.]


US Patent 5,678,343 – Safety lock for securing a replaceable barrel to the housing of an automatic weapon. [Not a One Rifle.]

Remington ArmsUS Patent 5,907,919 – Barrel mounting means, e.g. releasable mountings for replaceable barrels using screws or bolts. [Not a One Rifle.]


US Patent 6,655,372 – Quick detachable gun barrel assembly. [Not a One Rifle.]


I became the “go-to-guy” for LWRC’s director of engineering as a resource for CAD design, engineering, and light machine work.


Fast forward a year, I have been brought in to help LWRC with the design and engineering of its SABR, which would later become known as the REPR.

The “Sniper Assaulter Battle Rifle” project initially started as a barrel system intended to be removable within seconds and without tools. The objective was to present to the US Army a weapon system that could be quickly configured to different barrel lengths in the field, one rifle configurable for two roles: CQB and Sniper.


I was told by LWRC that the intended project would shift back to a fixed-barrel system because the design challenges of a quick-change barrel were too significant to become a viable product. I disagreed and pushed LWRC to pursue the original project, but they rejected my insistence. LWRC stated that it would never be accurate or repeatable without a barrel nut fixing the barrel and upper receiver together. Nonetheless, I complied with LWRC’s request to help them engineer the fixed-barrel SABR instead, from which prototypes were built.

Without having the intended capabilities desired, the SABR was pitched to the US Army Squad Designated Marksman Rifle program by LWRC as a platform that provides designated marksmen both QCB and Sniper roles in one weapon system. However, because the SABR was presented without a quick-change barrel system, LWRC instead proposed the idea that operators would carry an entire extra complete upper receiver having a 20” barrel concealed inside a large backpack, with a CQB short barrel rifle in hand having a 10” suppressed barrel.

For reference, see: The LWRC SABR 308 Sniper Rifle. Because of LWRC’s failure to deliver a quick-change barrel system, a field-configured multi-role weapon system remained a novel and unobtainable concept.


The Stage is Set: Paul Leitner-Wise was granted US Patent 7,313,883 on a quick-change barrel system for Armalite style rifles. [Not a One Rifle.]

Although his ‘883 patent remains uncommercialized, Paul Leitner-Wise set the stage for a new 21st Century race among top firearms designers & engineers to create and develop a manufacturable, reliable, and accurate quick-change barrel system for the AR-15 [i.e. the “One Rifle”].

Moving away from the One Rifle concept, LWRC renamed their SABR to REPR and rebranded the product solely as a DM/Sniper Rifle. With LWRC’s inability to deliver a multi-role weapon system, focus on the “One Rifle” faded, rarely to be brought up again. Yes start at year 20242009: I founded F&D Defense in Leander Tx and began what would become long-term, phased development of a multi-role weapon system that purposefully went against firearm engineering norms, at least as it related to the barrel attachment method and the piston gas system. With LWRC’s rejection of [or inability to pursue] a rifle design that could have reliable barrel swap capabilities, I was determined to accomplish such a design.

In this first phase of development, I intended to prove that other barrel attachment methods would perform just as well or better, also making assembly of the overall weapon system much easier. I began designing the FD308, to include a barrel that attached to the firearm without using a barrel nut. If this could be accomplished, the door would be opened to a quick-change barrel system which would then lead to a legitimate multi-role weapon system.


The result itself was a ground-breaking concept when the 4-bolt barrel attachment system came to exist. Spinning off from the AR-10 platform, I then developed the world’s first long-action AR on this same barrel attachment concept, the FD338 chambered in 338 Lapua Magnum. Removing the barrel nut would become the first necessary step towards achieving the One Rifle concept.


Each of these F&D weapon systems broke through multiple barriers at once, offering the first long range autoloading platforms capable of precision engagements between 1,000 yds and 1 mile. Equipped with the first and only delayed-gas piston system, US Patent 8,863,637, these unique weapon systems became the only large-frame piston-operated firearms capable of consistent sub-half-MOA accuracy. At that time, LaRue Tactical, JP Rifles, GA Precision, and Wilson Combat were the only AR-10 manufacturers offering a sub-MOA accuracy guarantee, all being direct impingement platforms. Manufacturers of piston-driven large frame ARs, at that time, were impressed to achieve 1.5-2 MOA accuracy, including those manufactured by POF and LWRC. As such, F&D Defense products provided the highest quality and most accurate AR-10 available, as well as the first AR-based long-action on the market.


F&D expanded its capabilities in New Braunfels, Tx with more ambitions. On May 15 2013, the FD308 was written about in Guns Magazine by Jerry Cannon. Control the Flow: The F&D Defense .308 Uses A Proprietary Gas System To Fine-Tune Barrel Harmonics


As LWRCI became threatened by F&D in the precision AR10 marketplace, LWRCI decided to sue F&D. As a direct result, my business partners became increasingly weak, so I sold my ownership in F&D and I retained manufacturing equipment and exclusive rights to produce parts for F&D. They moved F&D to Oklahoma and I moved back to my hometown of Henderson, Tx.

Remington Arms – US Patent 8,782,943 – Quick detach barrel mounting system. [Not a One Rifle.]

LaRue Tactical – US Patent 8,769,853 – Quick detachable handguard mechanism for firearms. LaRue Tactical attempts to create a takedown rifle, but later realizes that true “takedown” designs don’t require tools. The Firearm Blog – LaRue PredatOBR [Not a One Rifle.]


I continued producing parts in Henderson, Tx for F&D.

Daniel Defense DD5US Patent 9,658,020 Owner Marty Daniel saw the benefits of my 4-bolt barrel attachment system and adapted this into his DD5 platform. He then sought and acquired this patent on my prior art, which remains unenforceable for lack of proper inventorship and obviousness. [Not a One Rifle.]

Ruger – US Patent 9,057,576 – Firearm with quick coupling barrel system. [Not a One Rifle.]

SI Defense Inc – US Patent Application 20150308779 – Quick-release barrel firearm. [Not a One Rifle.]


I re-established my plans to continue developing the multi-role weapon system behind the scenes. Being back on my own, the Folding Barrel Interface was invented and many design challenges were presented. I worked day and night to wrestle through those challenges in order to create a barrel connection method that could fold and be repeatable [an entire chapter will be written about this another day]. I began on the AR-10 308 Win platform and again achieved consistent sub-half-MOA accuracy, verified Return to Zero capabilities to an immeasurable POI shift, and verified all safety aspects. The project was completed from concept to a functional fully-tested prototype in 4 months. For the next 12 months, I worked tirelessly to create a folding “mil-spec-ish” AR-15 platform that could be standardized for scalable manufacturing.

Cry Havoc Tactical QRBUS Patent 9,476,663 – Removable barrel and handguard for modular rifles. Being the only practical contender for a multi-role weapon system, this retrofit platform was adopted later in 2018 by the U.S. Air Force’s GAU-5A Aircrew Self Defense Weapon program. Although its reliability/accuracy and tool-less barrel swap capabilities are in-line with One Rifle requirements, its disassembled state and poor deployment speed [especially under stressed conditions] keeps this takedown platform from achieving “One Rifle” status. [Not a One Rifle.]

Ruger enters the market with its takedown AR-15: Ruger SR556 Takedown – Cool Design – Problematic Performance – Full Review [Not a One Rifle.]

LEO TakedownUS Patent 9,879,935 – Quick Takedown Firearm. Side story: FoldAR meets LEO Tactical at SHOT Show 2022 and a rapid deployment challenge ensues.The results were disastrous for LEO, with its barrel falling onto the floor. [Not a One Rifle.]


Following 2 years of making parts for F&D, I licensed the folding barrel interface for them to distribute my first sets of folding AR-15s. Knowing the practical cost from my 12 prior years in high-level production manufacturing, I was not interested in having to fund, build, and operate an entire firearm manufacturing and distribution business and F&D had no manufacturing capability. So the licensing deal made sense to both parties, allowing us to both pursue what we wanted.

In early 2017, I produced 250 pre-production folding barrel AR-15s for F&D. They named it the “XAR Invicta” and introduced it into the market as a hiking and camping self defense product… With big money and no direction or experience, it was not long before F&D failed its most basic licensing terms. With F&D unable to perform, I terminated the license and progress on the One Rifle concept took a serious blow.


Despite my desire, I started FoldAR as a scalable in-house manufacturing facility consisting of 2 production machines and 2 employees. With that, and an extremely tight budget, I pursued building the brand and business, releasing the FoldAR product line towards the end of 2018.

June: Corby Hall – US Patent 9,995,556 – The folding barrel interface patent was granted. [Not a One Rifle, yet.]


Soon after releasing the FoldAR product line, Texas A&M Engineering Extension’s [TEEX] law enforcement products testing division conducted Return to Zero and safety testing on the FoldAR. The product excelled beyond anyone’s expectations [except that it met my expectations] and earned its “TEEX Tested” certification.


In March, I secured a small loan to support and expand FoldAR’s business operations and I relocated its manufacturing and distribution from 2 locations in Henderson, TX into 1 location outside of Henderson with a testing range.


FoldAR was able to begin breaking into Law Enforcement markets with great success seen with School-Based Law Enforcement and School Resource Officers across the country.


The “One Rifle” materializes with FoldAR’s release of the MoBetta product line. With FoldAR products now having the most reliable and quickest caliber/barrel swap capabilities of any “takedown” rifle ever created, the “MoBetta” product encompasses all the requisite features of the coveted One Rifle, plus some. Being easy to manufacture, assemble, and operate, the MoBetta is objectively “more better” than any other AR-15 available by having achieved a true field-configurable weapon system without introducing compromises.

In addition to allowing an easily configurable weapon system, and combined with its unrivaled concealment capabilities, the MoBetta establishes its capacity to be the “One Rifle to Rule Them All”, leaps and bounds beyond the One Rifle concept.


Top industry influencers began publishing perfect reviews on the FoldAR MoBetta product, with each review demonstrating how simple, effective, and valuable the FoldAR MoBetta product is, while referencing MoBetta’s capacity to earn the title of “One Rifle To Rule Them All“. Sub-MOA accuracy, reliability, Return to Zero, quick caliber and barrel swaps, concealment, rapid deployment, and accuracy beyond 1,000 yards were all independently demonstrated to show that the MoBetta is the One Rifle to Rule Them All. Among the reviewers are:

As a result of these reviews and having each unique element of the MoBetta weapon system independently verified, the FoldAR MoBetta hereby claims title to “One Rifle to Rule Them All”.

August: FoldAR is established as the Sole Source Manufacturer of Concealed Carry Rifles, making it the best weapon system for School-Based Law Enforcement and School Resource Officers.


Against numerous attempts by evil over the course of 25 years to foil His plan, I am extremely grateful to have been chosen to invent, develop, and bring to market the One Rifle to Rule Them All. I am thankful for each of you who have supported this endeavor, whether you are one of the ~5,000 customers who have purchased my products, or one of those who have helped in many other ways.

The One Rifle to Rule Them All will live on forever and I am excited for the chance to watch it become the gold-standard by which all others are measured and further developed upon.

Co-Dedicated to

The Unknown Law Enforcement Officer

To the Unknown Law Enforcement Officer: On April 21, 1999 you cornered me in a juvenile detention center, and alone in solitary confinement, you instructed me to look into your eyes as you proclaimed your truth to me and stated with certainty: “You Caused Columbine”.

As your demon ramped up its attacks against our children over the years, it never realized that its plan was foiled, as His angels had already been assigned.

Although your lie would hurl me into decades of torment and strife, His angels continued beating down your demon. His One Rifle story would unfold, no matter the cost.

Today, as I stand outside of Columbine High School, I think about your words and ponder how it took me nearly 25 years to realize they were simply demonic lies spreading in an ancient battle being waged for souls.

To the Unknown Law Enforcement Officer: I forgive you. The One Rifle is Dedicated to you, as together, we will watch demons squirm from each FoldAR able to protect innocence from evil.

Colossians 3:13 “Bear with each other and forgive one another if any of you has a grievance against someone. Forgive as the Lord forgave you.”

Co-Dedicated to

Angel Martinez

Dear Angel Martinez,
December 24, 2023

On August 9, 2001, as demons kicked my turmoil into high gear, I faced one certain path at the age of 19, Federal Prison. As you investigated my crime with respect and empathy, you took the time to learn who I was.

Within that confined cell, you brought Grace with you. You took faith in the desire of my character when you had no obligation to do so. As our interview concluded, you instructed me to look into your eyes, and with your hand on my shoulder, you stated to me:

“Everything is going to be alright, you’re going to be alright.”

From the result of your compassion and His plan, I was given another chance to redeem myself. Having Zero interest in firearms or the military, 9/11 happened one month later and I would continue onward towards His plan, not mine. Pit-stop US Navy, then on to a career in advanced firearms development.
Today, as we meet again after 22 years, and in accordance with His plan, I present to you:

His One Rifle.

I Pray that our Officers will shield His children all day long, by what rests between their shoulders.

And I hope the One Rifle will fulfill my debt owed for your Grace given, in my greatest time of need.

Corby Hall - Inventor

Ephesians 2:8-9 For it is by grace you have been saved, through faith—and this is not from yourselves, it is the gift of God, not by works, so that no one can boast.

Deuteronomy 33:12 Let the beloved of the Lord rest secure in him, for he shields him all day long, and the one the Lord loves rests between his shoulders.

Psalm 82:3-4 Defend the weak and the fatherless; uphold the cause of the poor and the oppressed. Rescue the weak and the needy; deliver them from the hand of the wicked.