How to Change Your AR Pistol to an SBR

I’ve been searching for ultimate compact rifle for a long time. Reliability was my number one criterion, followed by shootability, the ability to attach a suppressor and, finally, portability. I’m not here to debate the merits of various firearms for this role. Of all of the products that fill that large niche, my personal preference is the Patriot Ordnance Factory (POF-USA) P-415 EDGE with a 10.5-inch barrel. It fits all of my requirements, but why the POF-USA? Reliability.   

Short barrels and suppressors can sometimes cause reliability issues. With a 10.5-inch barrel, one can experience malfunctions because the cycling/timing is off due to powder burn time. Some ammo will work, and some will not, especially with older ammunition, so many people have to change their buffer to a lightweight model to help cycling.

When the special operations community looked at this reliability problem, their solution was a carbine with a short-stroke gas piston. The P-415 uses a piston and operating rod to cycle the action with no return spring. The piston only actually moves around an inch when fired, the inertia of that movement continues the cycle. A five-position gas system allows for fine-tuning, especially important with a suppressor attached. The troublesome standard AR gas key is eliminated in favor of one that is integrally machined into the nickel boron-coated bolt carrier. Gone also is the gas impingement byproduct of heat and carbon blasting into the working parts of the receiver. Some have complained about the added weight of gas piston ARs. At 6.42 pounds unloaded, that is not an issue for me.

POF-USA

POF-USA was founded by the late Frank DeSomma, an accomplished aerospace engineer with a passion for firearms. Besides his own take on the short-stroke gas piston, DeSomma made other patented innovations to the AR family of firearms. The cam pin, a known failure point on the AR’s bolt carrier, is replaced on the P-415 EDGE with a roller system that reduces friction with the receiver and is less prone to breakage. Another innovation is the E2 extraction system. Extraction is the weak link in the AR-15 design, mainly as a result of the lack of body taper in the 5.56x45mm cartridge. To promote positive extraction, DeSomma engineered four channels machined into a portion of the chamber. These channels allow a small amount of propellant gas to flow backward, effectively pushing the spent case out of the chamber. When I interviewed DeSomma in 2015, he described it as the same concept as using a screwdriver to break the mechanical seal between two plastic buckets stuck together.

DeSomma’s reliability upgrades did what they were intended to do, earning POF-USA a stellar reputation for reliability. In 2013, the San Bernardino, Calif., Sheriff’s Office stress-tested a full-automatic 14.5-inch-barreled 7.62x51mm NATO POF carbine and published the results. The testing put 35,480 rounds through a single firearm. There were no malfunctions until round 23,500 when the buffer spring gave out. During the entire test, they did not experience a single failure to extract.  

ATF Brace Ruling

So, the make and model of my carbine were settled. Here's where things get tricky. In order to obtain a P-415 EDGE carbine with a 10.5-inch barrel, one has to purchase a Short-Barreled Rifle (SBR) version which requires an ATF Form 4, a several-month wait and a $200 tax stamp. The alternative was the buy the pistol version of the P-415 and attach a “shoulder stabilizing brace” which ATF ruled as a legal configuration on several occasions, even when fired from the shoulder. That all changed in January, 2023 when ATF published Rule 2021R-08F—the pistol brace ban. According to the rule, attaching a brace to a pistol of this style constitutes manufacturing an SBR and requires the filing of a Form 1. Ordinarily that form would require paying the $200 tax but, if the firearm was possessed prior to January 31, 2023, the tax is waived during the 120-day grace period.

I will walk you through the process if you wish to register your brace equipped pistol as a Short Barrel Rifle. For starters, you will need an ATF eform account, which can be completed on the ATF’s website. The ATF eform site is antiquated and, if you’re old enough to remember it, will give you nostalgia for the dial-up internet era.

What You Need

Before you begin, I recommend that you gather everything that you will need for your application. You will need the following. 

• A current photo of yourself that meets the passport-style guidelines of the ATF.
• A photo of the engraving/markings of the serialized receiver.
• Contact info for your local law enforcement official and specific information related to the firearm: serial number, barrel length, overall length, manufacturer and caliber.
• You’ll need to submit fingerprints as well. They can be submitted electronically using the EFS format or paper fingerprint cards can be mailed in using a cover letter that you’ll receive via email from the ATF. I used a company called PrintScan, which allows you to make an appointment for electronic fingerprints at the location nearest you—mine was a UPS store. Once you have this fingerprint file, you can use it indefinitely. 

Submission

When you have everything you’ll need, log onto the eform site and make sure that you see the red tab designating ATF Final Rule 2021R-08F. Fill in all of the relevant information, upload your photos and fingerprint file, and complete the application. The system is not intuitive, so allow for plenty of time — it also won’t catch your mistakes so double-check everything. Once complete, the system will send a confirmation email which includes a copy of the submitted Form 1.

I would recommend printing out a physical copy of the form and keep it with the brace-equipped firearm as proof that it is in compliance. A copy of the form must also be sent to the chief law enforcement official listed during the application process. If you are uncomfortable with the process or simply don’t have the time to spare, some online NFA vendors will complete your application for a small fee.

Approval times for Form 1s submitted electronically were running approximately 30 days before the 2021R-08F was published. My latest application took only 23 days. The rule will no doubt increase the approval times but the exact amount of time we can expect remains to be seen. Once the Form 1 is approved, there are no restrictions on what type of stock is affixed. Many individuals will no doubt opt for a true buttstock rather than a brace — I certainly will.      

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If you have any thoughts or comments on this article, we’d love to hear them. Email us at FirearmsNews@Outdoorsg.com.

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