.264 (6.5mm) Cal – Proof Carbon PXT Bolt-Action Custom Prefits
$1,049.00
PROOF RESEARCH – Industry Leading Bolt-Action Barrels
A New Era of Rifle Barrel Technology
The PXT story began around 2018, as the U.S. military pushed to extract greater performance from existing weapons platforms. That effort led PROOF into medium-caliber cannon barrel development and forced a complete reassessment of rifling profiles, twist rates, pressure, projectile behavior, and barrel manufacturing.
Designed for the Enthusiast
PROOF Research PXT carbon fiber barrel blanks combine next-generation rifling technology with the lightweight performance and precision that have defined PROOF barrels for years. PXT – PROOF Exponential Twist – is a complete rethinking of conventional rifling geometry and twist progression, engineered to reduce engraving force, minimize throat erosion, and create a smoother transition as the projectile engages the rifling.
By dramatically reducing rifling lead angle and smoothing projectile engagement into the bore, PXT technology helps reduce wear, improve consistency, and create less felt torque during firing for improved recoil control and the ability to stay on target more effectively.
In controlled testing, PXT barrels have demonstrated 30-100% increase in barrel life while maintaining the accuracy standards expected from a PROOF barrel.
Built around our proven carbon fiber construction, PXT barrel blanks provide exceptional stiffness-to-weight ratio and reduced overall rifle weight without sacrificing performance. Designed for custom rifle builders and gunsmiths, these blanks offer a premium foundation for lightweight hunting rifles, precision long-range systems, and modern high-performance rifle builds where consistency and durability matter most.
The Challenge – Higher Pressure Changed the Problem
By the early 2020s, that same conversation had expanded into small arms — from 5.56 up through .338. At the highest levels of weapons development, it became clear that certain applications would require significantly more energy on target. Achieving that meant pushing chamber pressures to roughly 80,000 psi, well beyond the more common 62,000 psi.
Initially, this presented major challenges on the ammunition side. Containing that level of pressure without case failure required extensive experimentation with materials and propellants. Once the ammunition began to produce the needed performance, it quickly became clear that the barrel itself would become the next performance hurdle.
Early efforts focused on stronger materials, higher heat tolerance, and advanced coatings. While helpful, PROOF viewed materials and coatings as secondary. Our experience developing and producing cannon barrels pointed us in a different direction: the primary issue was physics at the point of ignition.
Conventional Rifling – A Violent Start
In a conventional barrel, the bullet is forced forward, abruptly engages the rifling at roughly a 6° angle, and begins rotating at full speed within the first quarter inch of travel.
This creates a sharp pressure spike, accelerates barrel wear in the first two inches of the barrel, and places significant stress on the projectile.
The PXT Solution – A More Gradual, Controlled Transition
With PXT, we’ve reduced that initial engagement angle by approximately 95–98%, dramatically softening initial bullet engagement, reducing pressure spikes, and minimizing throat wear.
Where traditional barrels may start at twist rates of 1:7 to 1:10 at the breech, PXT barrels begin far more gradually — often in the range of 1:250 to 1:500 — before accelerating through the bore.
We also reimagined the rifling profile. Traditional sharp-edged rifling is efficient to manufacture and grips the bullet jacket aggressively, but it wears faster and can deform the projectile under high pressure. PXT uses a proprietary, smoother-edged profile that reduces bullet engraving force by approximately 30%, limiting deformation, reducing wear on the lands, and enabling a more gradual twist progression.
95–98% – Reduced Lead Angle
Softer initial engagement helps reduce pressure spikes and throat erosion.
30% – Lower Engraving Force
A smoother rifling profile reduces projectile stress and bullet deformation.
30–100% – Longer Barrel Life
Testing has shown measurable barrel-life increases before accuracy degradation.
Measured Results – Consistency, Accuracy, and Barrel Life
The result is a fundamentally different reality. Under traditional pressure levels, PXT barrels have demonstrated 30–100%
increases in barrel life before measurable accuracy degradation,
with longer barrels seeing the greatest benefit.
The reduced lead angle and refined rifling geometry significantly slow throat erosion, spreading degradation over more of the
bore and allowing for much higher pressures and velocities
without shortening the lifespan of a barrel.
PXT has also shown measurable improvements in consistency and accuracy. Across multiple ammunition types and lot
variations, we’ve observed repeatable reductions in group
sizes of 20–50% in controlled testing.
Why It Matters – Less Sensitive. More Repeatable. Built for the Future.
These barrels are less sensitive to bullet jump and powder charge due to the reduced rifling lead angle and smoother engagement of the projectile. That gives PXT the potential to reshape how shooters think about pressure, velocity, barrel life, and repeatable precision.
The end result? That’s yet to be determined, but we are very sure this will change the industry for decades to come.
Barrel Contour
Barrel Twist
Caliber, Length, Twist, Contour
264, 16.5, 7.5 PXT, Sendero, 264, 20, 7.5 PXT, Sendero, 264, 22, 7.5 PXT, Sendero, 264, 24, 7.5 PXT, Sendero
Manufacturer
Is it legal to buy guns online?
Yes, it’s completely legal to buy firearms online. It a simple task to make a purchase from an online gun store. First you make your purchase, then contact a local dealer to facilitate a FFL Transfer. A good dealer takes over from there and all you need to do is wait on a phone call for pickup.
What’s an FFL and why is it called a transfer?
FFL stands for Federal Firearms License, and an FFL transfer is simply the process of changing possession of a firearm from an FFL to another FFL or customer. In almost all cases, it is not legal to receive a gun at your home or transfer a gun across state lines without the involvement of a dealer. Having an FFL dealer receive your online purchase is what keeps this process secure, safe, and legal.
When you buy a gun online from an FFL, like our online gun store, federal law requires you to have it shipped to a dealer with a federal firearms license so they can conduct the background check and legally transfer the gun to you. When your chosen FFL dealer notifies you that your purchase from us has arrived, you just show up to your FFL’s licensed location, fill out ATF Form 4473, pass your background check, and take your new baby (or babies) home.
Once you complete Form 4473, they conduct the federal background check through the National Instant Criminal Check System, and you pay the FFL their transfer fee.
At this point your new gun has been properly transferred.
1. Select a local FFL
As you explore online resources to locate a nearby FFL for your firearm transfer, keep in mind that you must confirm they will actually accept your item and perform the transfer, and that their fee is reasonable. You wouldn’t want an FFL to receive your items if they charge super high fees or only conduct gun transfers for items purchased in their store. You can find an FFL dealer near you using our FFL Finder page.
2. Contact FFL and confirm transfer
Before buying a gun online, it’s best to have already contacted and secured an FFL dealer to conduct firearm transfers for you. So when speaking with them for the first time, confirm that they are willing to accept the firearm shipment and that you’re comfortable with the dealer’s fee. Some state and local jurisdictions may impose fees or additional paperwork that you have to complete, discuss this with the FFL dealer if you have any questions about the local transfer process. Once that’s established, you simply provide your contact information and communicate that you plan to purchase a gun online and have it shipped to them. Once you have completed the first transfer with them, it’s courteous to send them a heads-up the next time a firearm purchase will be sent to them for you to pick up. It helps them to know what item is headed their way and where it’s coming from.
3. Buy guns online
If you’re shopping with us, you can order online at any time, just browse our selection of handguns, long guns, silencers, and NFA firearms, then add the ammunition and accessories you need. It’s easy to explore our online gun store inventory, you can search by keyword, model, manufacturer, caliber, capacity, safety, and price. Select the firearms or parts you want, add them to cart, include the receiving FFL if you have it, then complete your payment.
4. How to transfer to your dealer from our Online Gun Store
To buy from our online gun store, there are 3 ways to get your receiving dealer in contact with us.
SUBMIT AN FFL DEALER YOU ALREADY KNOW
Already have your FFL dealer’s information? Enter the FFL number in the available box on the check out page then place your order.
SEARCH FOR AN FFL DEALER USING OUR TOOL
Need to locate a nearby FFL? Use our FFL Lookup page at any time. The “Federal Firearms License Search” feature also displays next to your shopping cart when you’re buying from us. Just make contact with the local FFL of your choice and confirm they’ll handle your transfer.
CONTACT YOUR DEALER AND HAVE THEM EMAIL US
Get your FFL to email us. It’s common policy for FFL dealers to not give out their license number to consumers, so all you need to do is establish communication between Mister Guns and your chosen FFL. If you’re buying online from Mister Guns, contact them and have them send their FFL information to ffl@misterguns.com. Make sure to include any invoice numbers and your customer name so we can match it to your order.
5. Go get your new gun
It’s here! Your local FFL will notify you when your shipment has arrived. Make sure you bring a government-issued ID with your picture and current address, licenses, or permits depending on your state and the items you have purchased. Inspect the firearm before accepting the transfer, complete necessary paperwork and background check, then accept firearm possession. Gun transfers and usage are always subject to government regulations, so keep up to date on how to stay in compliance with these regulations in your area.
Whether you’re a new gun owner or just new to the online buying process, you’ll find great deals and experience excellent customer service when you buy from our online gun store. Keep the purchase process simple and shop with Mister Guns, we handle all the logistics and paperwork for you to get your firearm, confirming your receiving FFL has a valid license, and managing transfer approvals, shipping, and tracking.
We ship firearms and related accessories to valid FFL (Federal Firearms License) dealers only. Customers must provide a copy of the receiving dealer’s FFL before shipment.
Shipping charges may vary based on the destination and weight of the package. All shipments are sent via a reliable and secure carrier with tracking information provided. Orders typically ship within 1-2 business days after payment and required documentation are received.
Delivery times may vary depending on the destination and carrier service selected. Customers are responsible for ensuring compliance with local, state, and federal regulations regarding firearm purchases and shipments. Any returns or exchanges must be made in accordance with our return policy, which may include restocking fees and return shipping costs.
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.264 (6.5mm) Cal - Proof Carbon PXT Bolt-Action Custom Prefits