This FX Impact M4 Extended - Copper is the fourth generation of what by now must be the most successful all-round PCP of all time. This ultra-accurate and multi-adjustable PCP air rifle has a modular base, making it suitable for virtually every shooting discipline. From benchrest to hunting and everything in between.

Compared to the previous model, the Impact M3, some radical and some more subtle changes have been made to bring the FX Impact M4 to yet a higher level while also improving usability. We’ll guide you through the most important features and changes. A so-called FX Impact M3 versus FX Impact M4.

AMP MKIII regulator

The Dual Regulator system has made room for a single AMP MKIII regulator with a brass piston. With that, it’s stronger and more consistent, with a higher refill flow thrown in too. Besides that, this single regulator is more than capable of withstanding high working pressures up to an impressive 170 bar (2500 psi). Note that working pressure is something different than filling pressure, with the latter being 250 bar (3600 psi). The regulator can be adjusted with a screw at the rear of the trigger inside the trigger guard.

Top plate with dovetail

The FX Impact M4 Extended - Copper has a revisited top plate. The plate is thicker, which gives more rigidity to the whole air rifle, and it now features a dovetail rail that allows you to slide the 30 MOA Picatinny rail exactly there where you want it. That Picatinny rail has become slightly longer too, giving you even more freedom in mounting. The forward tilt of the rail with 30 MOA, will offer you a broader adjustment range on the rifle scope if used on long distances.

Quick Set Trigger

In every aspect, the complete trigger unit is new. As the FX Impact M4 Extended - Copper is such a universal platform, FX has been looking at what was needed to make the trigger adjustable and refined in such a way, that it would suit all types of shooting. When hunting, you’d like a predictable long stage while in sport shooting, you’ll prefer a featherweight trigger with a refined glass-like breaking point. With the Quick Set Trigger, all it takes to change between these two is to adjust a single screw. Besides that, you can reposition the whole trigger unit, setting it further or closer. And both stages are adjustable, while the trigger blade is adjustable in height and rotation.

Power Plenum 750

With a regulated 75 cc air buffer, the FX Impact M4 Extended - Copper has plenty of air at the ready behind the valve to deliver plenty of power. Enough to give even the heaviest slugs the perfect velocity. The large capacity of the plenum also allows for a lower regulator pressure than would be the case with a smaller plenum.

On the left side of the system, the hammer spring preload is adjustable with the famed Quick Tune system. With this, the preload can be adjusted with a macro-adjustment wheel in 16 big steps (5-15 fps or 1.5-4.5 m/s), after which you can do some finetuning with the micro-adjustment wheel ((1-2 fps or 0.3-0.6 m/s). The more preload, the more air will be let through and the faster the projectile will be propelled.

And then there’s the Dual Hole transfer port in the barrel that’s a feature on most calibres. It means that the barrel sports two openings on opposite sides where air is let through. The small opening, marked with a ‘P’, is perfect for use with pellets. By twisting the barrel 180 degrees, a larger opening will be situated in front of the transfer port, allowing for more airflow (thus more power) for heavier projectiles, such as slugs. That’s why it’s indicated with an ‘S’.

Superior Heavy STX barrel

FX uses liners inside its barrels, where the rifling is pressed-in from the outside. This gives a very smooth inner surface with minimal friction. The Superior Heavy STX liner has a twist rate that’s perfected for use with slugs. As an added advantage, the liners can be quickly changed for another calibre or type of ammunition. The only thing that needs to be changed too is the pellet probe.

Adjustable shoulder piece

The buttstock of the FX Impact M4 Extended - Copper is adjustable in height. This can be done stepless by loosening a screw on the right side. That way, the perfect shooting stance can be obtained for all postures. The buttstock has a comfortable concave shape with plenty of grip.

UG1 grip

To bring the comfort of and feel with the weapon to a next level, the FX Impact M4 Extended - Copper is equipped with a new (AR15 style) UG1 grip with a more defined ergonomic shape and contact areas with plenty of grip.

High-capacity magazine

Even the magazine is renewed with new, stronger materials for durability. The internal mechanism is optimised so the rotating centre will turn smoothly and firmly with even the heaviest slugs loaded.

Accessory rails

Besides the dovetail mounted 30 MOA Picatinnyrail, the FX Impact M4 Extended - Copper now also features two Picatinny accessory rails on the sides. There’s also a Picatinny rail at the underside, placed perfectly for mounting a bipod. 

Two-sided cocking lever

The cocking lever has a comfortable big knob and it is placed on the right side of the FX Impact M4 Extended - Copper. However, the lever can very easily be reversed to the other side for those who prefer the lever on the left side of the PCP air rifle.

Please note: The FX Impact M4 comes pre-adjusted in an average state of tuning for average use. The maximum power stated in the specifications can be reached by using the multiple adjustment options on this air rifle.