FX Impact M4 PCP Air Rifle Review – The Ultimate Adjustable PCP Air Rifle

The FX Impact M4 PCP Air Rifle represents the latest evolution of one of the world’s most respected air rifle platforms. Designed and manufactured in Sweden by FX Airguns, the Impact M4 combines cutting-edge engineering, exceptional accuracy, and unmatched adjustability, making it a top choice for competitive shooters, hunters, and long-range airgun enthusiasts.

Built on the success of previous Impact models, the M4 introduces several performance upgrades, including the AMP MKII regulator, Power Plenum 750, improved trigger system, and a stronger optics rail. Whether you’re shooting pellets or slugs, the FX Impact M4 delivers the precision and versatility expected from a premium PCP air rifle.

Why Choose the FX Impact M4?

The FX Impact M4 is designed for shooters who demand complete control over their rifle’s performance. Nearly every aspect of the rifle can be adjusted externally, allowing you to fine-tune power, air efficiency, and shot consistency without disassembling the rifle.

From precision target shooting to small game hunting and long-range competitions, the Impact M4 adapts to your preferred shooting style with ease.

Key Features of the FX Impact M4

• Pre-Charged Pneumatic (PCP) air rifle
• Adjustable AMP MKII regulator
• External macro and micro hammer spring adjustment
• External valve control adjustment
• Quick Tune System for fast tuning
• Smooth Twist X (STX) Superior barrel system
• Interchangeable barrel liners and caliber conversions
• Power Plenum 750 for increased efficiency
• Side-lever cocking action
• Match-grade adjustable trigger
• AR-style UG1 pistol grip
• Adjustable rubber buttpad
• Dual WIKA pressure gauges
• Carbon fiber air cylinder
• Picatinny optics rail with integrated 11mm dovetail
• Multiple Picatinny accessory rails
• Threaded barrel for moderator compatibility

Unmatched Tuning & Performance

The FX Impact M4 is built around one of the most advanced tuning systems available in a production PCP rifle.

Its externally adjustable regulator, hammer spring tension, valve control, and Quick Tune System allow shooters to optimize the rifle for different pellet weights, slugs, calibers, and shooting distances.

Whether your priority is maximum power, improved air efficiency, or tighter shot groups, the Impact M4 provides virtually unlimited tuning possibilities.

Smooth Twist X Superior Barrel System

One of the standout features of the Impact M4 is the FX Smooth Twist X Superior (STX) Barrel System.

This modular system allows users to:

• Change calibers
• Swap barrel liners
• Choose different twist rates
• Optimize performance for pellets or slugs

The result is exceptional accuracy across multiple shooting disciplines without needing to purchase an entirely new rifle.

Improved Power & Air Efficiency

The redesigned Power Plenum 750 increases available air volume while maintaining excellent shot consistency.

Combined with the AMP MKII regulator, the rifle delivers impressive power without sacrificing efficiency, making it ideal for both hunting and long-range precision shooting.

Maximum energy levels include:

• Up to 35 FPE (.177)
• Up to 87 FPE (.22)
• Up to 100 FPE (.25)
• Up to 125 FPE (.30)

Built for Comfort & Precision

The FX Impact M4 is designed to be comfortable during extended shooting sessions.

Features include:

• Forward-mounted reversible side lever
• Lightweight match trigger
• Height-adjustable buttpad
• Ergonomic AR-style grip
• Manual safety
• Improved top rail for greater rigidity
• Adjustable optics mounting position

These upgrades improve both handling and shooting accuracy in the field or on the range.

Available Configurations

The FX Impact M4 is available in several barrel lengths and calibers to suit different shooting applications.

Standard Model

• 600mm barrel
• 480cc carbon fiber bottle
• Available in .177, .22, .25 and .30

Sniper Model

• 700mm barrel
• 580cc carbon fiber bottle
• Increased shot count and velocity potential

Extended Model

• 800mm barrel
• 580cc carbon fiber bottle
• Optimized for long-range precision and maximum power

FX Impact M4 Specifications

Feature	Specification
Powerplant	PCP
Maximum Fill Pressure	250 BAR (3,625 PSI)
Regulator	AMP MKII Adjustable
Trigger	Match Grade Adjustable
Barrel	FX Smooth Twist X Superior
Air Cylinder	Carbon Fiber
Cocking System	Side Lever
Magazine	Side-Shot Rotary Magazine
Optics Rail	Picatinny & 11mm Dovetail
Accessory Rails	Picatinny
Safety	Manual AR-Style

Why the FX Impact M4 Is So Popular

The FX Impact platform has earned a reputation as one of the finest PCP air rifles available thanks to its:

• Outstanding accuracy
• Advanced tuning capabilities
• Premium Swedish engineering
• Modular caliber system
• Excellent air efficiency
• High-quality construction
• Strong aftermarket support

Whether you’re competing in benchrest matches, hunting small game where permitted, or pushing the limits of long-range airgun shooting, the Impact M4 offers the performance and flexibility to excel.

Buy the FX Impact M4 at SummitArms

At SummitArms, we offer the FX Impact M4 PCP Air Rifle together with premium pellets, slugs, scopes, moderators, bipods, compressors, air tanks, and shooting accessories. Our carefully selected range of high-performance airguns is backed by competitive pricing and dedicated customer support, helping you get the most from every shot.

Explore the FX Impact M4 today and discover why it remains one of the world’s most advanced and highly regarded PCP air rifles.