Barrel Rigidity for Slug Shooting of 90+ FPE

The advancement of slug shooting and the enhancements to the FX Impact have shooters wanting to use heavier slugs at faster speeds. Higher powers require a more rigid barrel to handle these projectiles’ additional energy and vibrations. The new FX Tensioned Barrel System adds the firmness needed to let you reach the potential of the FX Impact with heavy slugs, all while maintaining the extreme accuracy everyone expects from an FX Airgun.

From a barrel harmonics perspective, the tensioner system reduces the amplitude of barrel movement, which results in better accuracy and more consistency. Secondarily the rigidness of the barrel becomes more temperature stable and will further hold zero regardless of conditions or accidental knocks to the barrel.

The FX Tensioned Barrel System will be sold both as an add-on system that can be used with any existing 700mm STX barrels or sold with a barrel as part of a complete FX Slug Tensioned Barrel Kit. The tensioned barrel system should be used in unison with the FX Carbon Fiber Barrel Liners Sleeves for optimal accuracy.

Tensioner System 700mm with Carbon Fiber Sleeve – Art no: 20712


Unlock the power capabilities with a tungsten hammer!

Slug shooting requires higher pressures to move the additional weight and bearing surface that slugs have. In addition, with longer barrels, speed can be increased upon firing if the valve can remain open longer. Higher powers are achieved with a first-ever in the airgun world: the Tungsten Hammer Weight.

Tungsten is a material that is 1.7x denser than steel (used for the standard FX hammers). This extra weight hits the valve with more power which allows the valve to open even at higher regulated pressures and stay open longer

before closing.

The Tungsten Hammer is instrumental with longer barrels (700mm & 800mm) as the longer the barrel, the more desirable it is to have the valve stay open (ideally to just before the slug leaves the barrel).

Note that those shooting standard pellets will not see benefits from the Tungsten Hammer.

Impact M3 – Art no: 20710

Maverick/Wildcat MkIII/Dreamline/Crown/Panthera – Art no: 20699


This simple kit brings some key modifications to the rifle to maximize the power and accuracy potential of the Impact, especially when using slugs. Velocity increases are achieved in large part to the addition of two hammer weight spacers that placed in front of the return spring on the hammer weight guide. This allows for more compression on the hammer spring as well as adding more weight to the overall hammer. Working in harmony with this modification is a lighter valve return spring. This lighter spring allows the valve to stay open slightly longer which allows more air through to propel heavier projectiles like airgun slugs. 

Impact M3 Art no:  20340
Comes with a .22 caliber pin probe as well as a sleeve that slides over to create a .25 caliber pin probe.

Crown Art no: 20668

Maverick/Wildcat MkIII  Art no: 20369

Dreamline Art no: 20714


Harmonic Barrel Tuner 1/2″ UNF

This tuner takes the core rotating tuning weight from the Integrated Shroud and places it in a removable unit for use with any 1⁄2” UNF threaded airgun! It also includes and utilizes the air stripping effects of the caliber specific muzzle threads.

Dampening is further enhanced by de-resonating rings that have been engineered into the base of the shroud that squeeze the barrel and further reduce vibrations through the barrel. These above features, when combined with the recently released FX Carbon Fiber Liner Sleeve, absolutely stiffen the barrel system which further lowers the barrel’s harmonic amplitude (or whip) throughout the entire shot cycle. Both factors combined, create tighter shot groups, but are only part of the overall barrel tuning that this FX system brings.

*Not recommended for long/free floating barrels.

Art no: 20595



The FX Integrated Harmonic Barrel Tuner offers both dampening and tuning features that will have you obtaining new heights of accuracy from your FX Airgun. The shroud of the Harmonic Barrel Tuner first works to dampen the barrel, making the harmonic signature of the barrel quieter, more subdued, and controllable.

The finishing touch is found in the integrated rotating running weight located on the end of the shroud. Made from a specifically selected metallic alloy, this allows the running weight to have enough mass to affect the weight distribution of the overall barrel system. Shooters will find that even the smallest amount of rotating adjustment of the tuner weight by only a few thousands of an inch can change how your gun shoots groups, especially when shooting medium to long range distances.

500 mm – Art no: 20592

600 mm – Art no: 20593

700 mm – Art no: 20594


How to Install Integrated Harmonic Barrel Tuner

With barrel installed on rifle simply twist shroud counterclockwise to remove shroud from the barrel and carefully slide off of barrel.

Slide new shroud over barrel and line up internal treads to the barrel.

Twist harmonic tuner shroud clockwise to tighten.

Your new harmonic tuner is now installed and ready for testing.