This barreled action is for the shooter who wants to build a lightweight rifle in their own stock or chassis. It pairs Defiance’s lightest action with a PROOF PXT carbon fiber pre-fit barrel, so you start with a precise, lightweight core and choose the rest.
Action: Defiance Machine anTi X
The anTi X was selected because it is one of the lightest actions Defiance makes, at 22 oz in a medium action, without giving up steel construction. The receiver is machined from one piece of pre-hardened 416 stainless steel, and the bolt is machined from one piece of pre-hardened 4340 chrome moly. That combination gives you the smoothness, reliability, and longevity Defiance is known for.
The integral recoil lug and integral 20 MOA Picatinny rail remove extra parts from the build, so there’s less to install and less that can shift. The full-length lug ways are wire EDM-cut to hold close tolerances and limit stress in the receiver. Deep bolt fluting, a fluted firing pin, and a hollow bolt knob save weight. Defiance’s primary extraction design increases initial extraction for smooth bolt cycling. The anTi X shares the same guaranteed headspace measurement, +/- .001", as the Defiance Ruckus, Renegade, anTi, and Classic actions.
The anTi X uses a standard Remington 700 footprint, so it fits a wide range of off-the-shelf stocks and chassis. The Wyatt 3006/300WM cut works with hinged floorplates or center-feed magazines.
Barrel: PROOF Research PXT Carbon Fiber Pre-Fit, Sendero, PXT
The PROOF PXT pre-fit barrel is at the heart of this barreled action. PXT stands for PROOF Exponential Twist, a new approach to rifling geometry and twist progression. Instead of a conventional fixed lead angle, PXT reduces the rifling lead angle and smooths how the bullet engages the bore. That lowers engraving force, reduces throat erosion, and creates a smoother transition as the bullet enters the rifling.
For the shooter, that means less felt torque during firing, so the rifle stays steadier and you stay on target. It also means longer barrel life. In PROOF’s controlled testing, PXT barrels have shown significant increases in barrel life while holding the accuracy standards expected of a PROOF barrel.
As a pre-fit, the barrel comes from PROOF already chambered and threaded, made to shoulder directly to Defiance actions with no additional machining. Because it works with Defiance’s guaranteed headspace, you get a premium barrel and action pairing without the wait of a custom-cut barrel. The same system makes a future barrel swap simple when it’s time to rebarrel.
The carbon fiber construction is up to 64% lighter than a steel barrel of similar contour. The aerospace-grade carbon fiber wrap also improves heat dissipation for cooler, longer-lasting performance.
Why It Performs
This barreled action isn’t a collection of good parts; it’s a system. The anTi X keeps weight down with integral features and premium steel. The PROOF PXT pre-fit barrel delivers accuracy and long barrel life at a fraction of the weight of steel, and it is ready to go from day one. Drop it into the Remington 700 footprint stock or chassis of your choice, and you have the core of a lightweight rifle you can trust.
Call 850-537-2818 or email info@altusshooting.com for availability.
Shipping and Compliance
This item must be shipped to your local licensed FFL dealer. Please select your FFL during checkout. Questions? Email info@altusshooting.com
All ATF serialized items will ship UPS Ground with signature required. Please contact us if you need expedited shipping.
