Earlier this week, we published a story recounting the comprehensive saga of Franklin Armory’s novel, new rifles, the ATF’s attempt to illegally classify them, the court battle that ensued, and the legal outcome.
On September 25, the ATF dropped another unsigned open letter in which it “…instructed Franklin Armory that it needed to retrieve the weapons it had previously sold.”
The letter is an order referring to Franklin Armory’s offering of the “Antithesis” AR-type firearm in a new 5.56 caliber.
Before we review the new letter and its significance, you can catch up by reading the original story here. Alternatively, here is a simple summary to bring the reader up to speed:
- 2019 – Franklin Armory made a new kind of firearm.
- 2019 – The ATF couldn’t classify it into existing GCA / NFA categories, so the ATF illegally tried to shoehorn it into another category.
- 2023 – Franklin Armory took the ATF to court to challenge the classifications.
- 2025 – The ATF lost the court battle when a judge nullified its classifications, and they entered into a settlement.
- 2025 – Franklin Armory introduced and began selling a variant of the new firearm, and separately prototyped a new type of ammunition. The new firearm was wildly popular.
- 2025 – The ATF issued a new open letter instructing Franklin Armory to retrieve all copies of the 5.56 caliber Antithesis sold and issue refunds, under the threat of prosecution.
New Letter, New Edict
As outlined in our story above, after a multi-year legal battle, the ATF was forced in a settlement to classify the Antithesis as a “firearm” under the Gun Control Act (but not a “rifle” under the Gun Control Act or a “firearm” under the National Firearms Act).
The ATF acknowledges that, “The court held that the Antithesis did not legally constitute a ‘rifle’ because it was designed and intended to fire both single-projectile (.45 Long Colt) and multi-projectile (.410 caliber shotshell) ammunition.” Put simply, because it was designed to fire more than one type of round, including a multi-projectile round, the firearm is not a rifle according to that legislation.
(U.S. Code defines a rifle as, “a weapon designed or redesigned, made or remade, and intended to be fired from the shoulder and designed or redesigned and made or remade to use the energy of the explosive in a fixed cartridge to fire only a single projectile through a rifled bore for each single pull of the trigger . . .”)
The narrative in the September 25 open letter continues:
On August 28, 2025, Franklin Armory submitted to ATF for classification a 5.56mm AR-type rifle under the “Antithesis” brand. This rifle had a barrel chambered for 5.56mm NATO, with standard rifling. The barrel was 7.5 inches long, with a 1:9 twist. Thus, the rifle was the same as other standard AR-type short-barreled rifles.
It’s important to recap here a couple of points to ensure the narrative is clear:
- The original Antithesis was a conventionally rifled, short-barreled firearm designed to fire .410 bore shotshells, slugs, and .45 Colt cartridges.
- The court held that the Antithesis did not legally constitute a “rifle” because it was designed and intended to fire both single-projectile and multi-projectile ammunition.
- Following the court decision and settlement, Franklin Armory offered the Antithesis in 5.56 caliber, rifled, short-barrel options.
Continuing the story, the ATF notes that, along with submitting the new firearm for classification, Franklin Armory also submitted a new, novel type of ammunition:
Franklin Armory also submitted a sample of an exotic prototype 5.56mm caliber saboted ammunition that housed multiple smaller projectiles in a casing. That ammunition could be used not only with the rifle Franklin Armory submitted on August 28, but also with every other firearm chambered in 5.56mm NATO. Pointing to the July 2025 settlement agreement, Franklin Armory asserted that because its new submission could shoot a multiple-projectile load, it was not a “rifle” under the Gun Control Act or the National Firearms Act.
Connecting the dots, the new 5.56 caliber Antithesis could fire a novel, new ammunition that housed multiple projectiles — the very condition upon which the court allowed the previous determination that the Antithesis is a “firearm” under the Gun Control Act (but not a “rifle” under the Gun Control Act or a “firearm” under the National Firearms Act).
What exactly did the ATF take issue with? First, it objected to the fact that Franklin Armory sold the new model without ATF permission:
Before ATF reached a classification, Franklin Armory proceeded to advertise online and sell an Antithesis-branded rifle in at least three different models…
The ATF also contends that:
…all three Antithesis-branded firearms are standard AR-type rifles, no different from other short-barreled AR-type rifles sold by other manufacturers.
It further asserts, “Unlike the FAI-15 Antithesis chambered in .410/.45 Long Colt–the subject of the July settlement agreement–these weapons were not designed to shoot both single-projectile ammunition and shotgun shells.”
Here the ATF is relying on the statutory definition of a rifle, which leans heavily on the concept of intended design (see definition above). The main argument it puts forth is that the new rifle wasn’t designed any differently than other 5.56, AR-pattern rifles.
Does the new, prototyped sabot ammo have any impact? Not according to the ATF:
Franklin Armory’s contemporaneous submission of an exotic 5.56mm ammunition that could be used in any 5.56mm chambered rifle reflects, at most, the design of new ammunition. It says nothing about the design of the rifle Franklin submitted in August–the sole relevant question under the statutory language.
The ATF argues that it’s an absurd position to think that a new kind of ammunition would change the statutory classification of a firearm, noting that:
If that were true, the existence of such ammunition would render the concept of a statutory rifle a null set. That is not only a legal absurdity, but also–even if correct–could have unintended legal consequences for purchasers of AR-type rifles.
It does, however, beg the question of the absurdity of the other side of the position: Why do arbitrary features like barrel length and rifling potentially have severe legal consequences for purchasers of firearms?
Nevertheless, the ATF summarizes its argument with what seems like a not-so-thinly veiled threat:
Unfortunately, Franklin Armory falsely represented to consumers that these weapons are not “short-barreled rifles” and that they could be transferred without complying with the National Firearms Act. In doing so, Franklin Armory was putting consumers in legal jeopardy because they could be subject to prosecution by any future administration.
The threat itself begs the question: Is the ATF insinuating that under this administration, it would not prosecute consumers who purchased these rifles?
The ATF ends the letter claiming it is providing “…a reasonable path forward by properly registering the weapons under the National Firearms Act and transferring them according to the requirements of the Gun Control Act and National Firearms Act.”
This letter raises more questions than answers and is certainly not the end of the story.
News2A reached out to Franklin Armory for comment on this story, but did not receive a response.
