Maximum volume. Maximum silence. No compromises.
The Bushmaster Carbon Sound Mitigator – Big Boy* is the absolute peak of sound suppression in the Bushmaster lineup. If your goal is to play as sneaky as humanly possible and make your HPA replica nearly disappear acoustically, this is the Sound Mitigator you run.

This is the quietest model available. Period.

And only about 166 grams

*previously called Compensator

Design Philosophy

The Big Boy exists for one reason: ultimate silence.
By increasing internal volume to the maximum practical size, this Sound Mitigator delivers the highest level of sound reduction possible without adding noticeable weight or negatively affecting handling.

Despite its size, the Fat Boy remains surprisingly lightweight, meaning you won't feel it during gameplay — but everyone around you definitely will.

This model is trusted and used by top-tier stealth players, including Kicking Mustang, who runs the Big Boy on his SRS / TAC41 sniper setups specifically because it is the quietest option available.

Available Size (Model Big Boy)

• 180 mm / 18 cm
  Designed for players who want the absolute best sound reduction available.

Compatibility

• 14 mm CCW (counter-clockwise) M4 outer barrels

• Plug & Play — no modifications required

• Compatible with all 14 mm CCW outer barrels (MTW, VSR 10 with adapter, AEGHPA conversions, Gate PTX pistol)
  
  

Performance Notes (Important)

• Recommended for HPA replicas only
  AEG and GBB platforms gain minimal benefit from any Sound Mitigator.

• On HPA, this is as quiet as it gets —
  the difference is immediately and unmistakably noticeable.

Proof & Support

• Instruction videos available on YouTube: callsign.bushmaster

• Backed by extensive real-world testing and community feedback

Bottom line:
The Bushmaster Carbon Sound Mitigator – Big Boy is the end boss of silence. If stealth is your priority and you want the quietest possible HPA setup, this is the Sound Mitigator you choose — no further upgrades needed.

FEATURES AND SPECS

Key Features

• Extreme internal volume
  Large-diameter design maximizes sound absorption.
• Full carbon construction
  Ultra-light, rigid, and strong enough for serious field use.
• Studio-grade acoustic foam
  Custom-cut internal foam rings for maximum suppression efficiency.
• Integrated "fart flap" system
  Eliminates air exit noise and pressure pop common on HPA platforms.
• Hand-built & extensively field tested
  Tested by the builder, teammates, and 1000+ players across multiple countries.

Technical Specifications

• Model: Fat Boy
• Diameter: 60 mm
• Length: 180 mm
• Material: Carbon fiber
• Weight: Ultra-light (despite size)
• Mount: 14 mm CCW