FX Impact M4 800mm Extended Air Rifle

A New Standard for the Modern PCP — Unmatched Adjustability | Power Plenum 750 | Rigid Top Plate | Interchangeable Calibers

The Swedish powerhouse raises the bar yet again. With the release of the FX Impact M4, FX Airguns hasn't just left a lasting "Impact" on the airgun industry—they've set a new standard for what a modern PCP air rifle should be. The M4 pairs the AMP MKII regulator, external micro/macro hammer-spring tension adjustment, and external valve control for a level of tunability never before seen in the airgun world. The possibilities are seemingly endless!

Built to do just about anything. From small and medium game hunting to topping the field at a 100-yard benchrest match—the M4 comes ready. Pick one up today and unlock your shooting potential!

Why Choose the Impact M4?

• ✅ Unmatched Adjustability — AMP MKII regulator + external hammer spring + valve control
• ✅ Quick Tune System — Virtually tool-free adjustments
• ✅ Improved Power Plenum 750 — Wider power range without sacrificing shot count
• ✅ Smooth Twist X (STX) Barrel — Interchangeable calibers & twist-rate liners
• ✅ New Rigid Top Plate — Thicker & stronger than the M3 for enhanced performance
• ✅ Customizable Scope Rail — 30 MOA Picatinny on 11mm dovetail, fully positionable
• ✅ Rear Power Block — Superior power transfer, ideal for heavy slugs
• ✅ Dual Transfer Ports (.22/.25) — One for pellets, one for slugs
• ✅ Forward Reversible Side-Lever — Blistering-fast follow-up shots
• ✅ UG1 AR-Style Grip & Safety — Ergonomic, ambidextrous comfort
• ✅ Quick Set Match Trigger — Lightweight, two-stage adjustable
• ✅ Four Calibers — .177 / .22 / .25 / .30

Description

With the release of the FX Impact M4, the Swedish manufacturer has not only left a lasting "Impact" on the airgun industry—they have set a new standard for what a modern PCP air rifle should be. The Impact M4 features the Adjustable Match Precision MKII (AMP) regulator, external micro and macro hammer spring tension adjustment, and an external valve control adjustment. Together, these features represent a level of adjustability never before seen in the airgun world. While you may not need or want to alter these adjustments, the ability to test different settings and see their performance is at your fingertips.

Endless Adjustability

The adjustability doesn't stop there. The Impact M4 utilizes the Smooth Twist X Superior barrel liner system that allows for interchanging calibers. Maybe more importantly, the system lets users purchase different liners with different rifling twist rates tailored to specific ammo. And with the improved Power Plenum 750, output performance adjustability is enhanced even more—a wider power adjustment range without sacrificing shot count!

Ergonomic by Design

No detail was overlooked. Shouldering the rifle highlights its ergonomic friendliness. The new UG1 AR-style grip and safety switch are welcome, comfortable features for many shooters, and the stock is capped with a vertically adjustable rubber buttpad. Perhaps the most user-friendly feature is the forward-mounted reversible cocking lever that cycles the high-capacity magazine with ease. Follow-up shots come at blistering speed, and the lightweight Quick Set match-grade adjustable trigger lets you place shots with extreme precision.

The Power Block

Carried over from the previous version, the rear Power Block handles power transfer much like a car's carburetor while the plenum stages the power capabilities. It's especially useful for shooting heavy slugs—pressure in the plenum better translates to pressure behind the slug upon firing, allowing higher speeds and power. Slug shooters are encouraged to add the FX Impact Tungsten Hammer Weight for higher working pressures.

New Rigid Top Plate & Rail

A welcome new addition is the rigid top plate and new scope rail system. The top plate is considerably thicker and stronger than the M3's, enhancing the shooting experience and performance. The top rail has an 11mm dovetail machined into it, on which the longer Picatinny scope rail rides—letting you customize rail position for just the right eye relief. You can even remove the Picatinny rail and mount directly onto the 11mm dovetail.

A Caliber for Every Job

The FX Impact M4 comes in four calibers. The .177 is perfect for target practice or hunting small game like squirrels; the .22 and .25 excel at small game and pests like groundhogs; and the .30 can be used for medium-sized game animals.

Power & Shot Counts

Specifications

Key Features in Detail

• Industry-Leading Tunability — AMP MKII regulator with external macro/micro hammer-spring and valve control, all part of the virtually tool-free Quick Tune System.
• Wider Power, Same Shot Count — The improved Power Plenum 750 expands the power adjustment range without sacrificing efficiency.
• Astonishing Accuracy — The Smooth Twist X Superior barrel system with interchangeable calibers and ammo-specific twist-rate liners.
• Stronger Foundation — A new rigid top plate (thicker and stronger than the M3) with a fully positionable 30 MOA Picatinny-on-11mm-dovetail rail.
• Slug-Ready Power Block — Better translates plenum pressure to the slug for higher speed and power (add the Tungsten Hammer Weight for higher pressures).
• Fast & Precise — A forward-mounted reversible side lever for blistering follow-ups and a lightweight Quick Set match trigger for pinpoint shots.
• All-Day Comfort — FX UG1 AR-style grip, AR-style manual safety, and a vertically adjustable rubber buttpad.