The FX Impact M4 Extended Copper is a 6.35 mm PCP air rifle built around a long barrel, high air capacity and extensive adjustability. Its 800 mm Superior Heavy STX barrel is particularly suited to slugs, while the 75 cc Power Plenum 750 provides a substantial reserve of regulated air behind the valve. Maximum stated power for this configuration is 135 J.
Adjustability remains one of the defining characteristics of the Impact M4. In addition to regulator adjustment, the valve and hammer spring can be fine-tuned to suit the chosen projectile and setup. The Quick Tune system provides both macro and micro adjustment for hammer spring preload. On calibres equipped with the Dual Hole transfer port, airflow can also be configured for pellets or heavier slugs.
The M4 generation introduces the Quick Set Trigger, allowing the trigger characteristics to be adapted for different shooting disciplines. It can be adjusted from a predictable hunting-style setup to a light competition-oriented trigger, while trigger position and individual stages can also be refined. The ergonomic UG1 grip provides a comfortable and controlled hold.
A 580 cc carbon-fibre bottle with a maximum fill pressure of 250 bar provides a substantial air supply. For optics, the rifle uses a 30 MOA Picatinny rail, complemented by additional Picatinny accessory rails. The 30 MOA inclination helps preserve scope adjustment range when shooting at longer distances.
The reinforced M4 top plate increases rigidity, while its dovetail arrangement allows the optic rail to be positioned as required. The redesigned high-capacity magazine uses stronger materials and an updated internal mechanism intended to maintain smooth rotation even with heavy slugs.
The side lever is fitted on the right as standard but can be moved to the left. Together with the adjustable buttstock, modular STX barrel system and extensive tuning options, these features make the Impact M4 Extended a versatile platform particularly well suited to precision and benchrest shooting.