The SilencerCo Delta Adapter for FN Five-seveN (brand part number AC77) gets a 5.7x28mm pistol suppressor-ready in a matter of seconds by adapting the Five-seveN’s native M10x1 muzzle threads to a standard 1/2×28 pattern. Silencer Co built the Delta line around O-ring engagement, which keeps the muzzle threads clean and prevents the suppressor from working loose during firing, a common annoyance with simpler thread adapters. Delta accessories in this thread pattern are compatible with the Switchback 22, Sparrow 22, Spectre 22, Warlock 22, and Osprey Micro 22 suppressors, giving Five-seveN owners access to SilencerCo’s rimfire and pistol-caliber suppressor lineup. It is a simple, purpose-built accessory rather than a suppressor itself.

Key Specifications

• 5.7x28mm caliber matches the FN Five-seveN.
• Adapts M10x1 native threads to 1/2×28.
• O-ring engagement keeps muzzle threads clean.
• Prevents suppressor loosening under firing.
• Compatible with the Switchback 22, Sparrow 22, Spectre 22, Warlock 22, and Osprey Micro 22.
• Delta model line from SilencerCo.
• Gets a suppressor mounted in a matter of seconds rather than requiring a separate barrel swap.

Frequently Asked Questions

What pistol does this adapter fit? The FN Five-seveN, adapting its native M10x1 threads to 1/2×28.

What suppressors work with this adapter? SilencerCo’s Switchback 22, Sparrow 22, Spectre 22, Warlock 22, and Osprey Micro 22.

Is this adapter itself an NFA item? No, it is an ordinary Title I accessory; only the suppressor it mounts is a regulated Title II item.

Buy the SilencerCo Delta Adapter for FN Five-seveN

Get your Five-seveN suppressor-ready with a secure, O-ring-sealed adapter. Order it from our Lubbock, Texas gun shop for fast, insured shipping, and browse more Class 3 parts and accessories.