The Radical Defense CS3 .30 caliber suppressor is a hub mount can that locks onto a KFM flash hider threaded 5/8×24. Radical Defense rates the CS3 for .30 caliber, which covers the 7.62mm rifle cartridges commonly run through AR-10 and AR-15 pattern rifles. The KFM flash hider threads onto the barrel and the suppressor mounts to it, so the can does not thread directly onto the muzzle. That setup lets the suppressor come off while the flash hider stays put. It is a practical pick for a shooter who wants a hub-mounted .30 caliber suppressor on a 5/8×24 barrel.

Key Specifications

• Caliber rating is .30 caliber, the bore class that covers 7.62mm rifle cartridges.
• Mounting is through a hub mount, which locks the suppressor onto its muzzle device.
• The muzzle device is a KFM flash hider, Radical Defense’s attachment point for the suppressor.
• The KFM flash hider threads on at 5/8×24, the common thread on .30 caliber AR-pattern barrels.
• The suppressor does not thread directly onto the barrel; it mounts to the flash hider, so the barrel threads see no wear from mounting the can.
• With the can removed, the flash hider stays on the rifle and keeps doing its job.

Frequently Asked Questions

How does the CS3 mount? Through a hub mount onto a KFM flash hider. The flash hider threads onto a 5/8×24 muzzle, and the suppressor locks onto it rather than onto the barrel.

What calibers does the CS3 cover? Radical Defense rates it for .30 caliber, the bore class used by 7.62mm rifle cartridges.

Do I need ATF approval to buy this? No. As of October 9, 2026, ATF no longer requires Form 4 approval, registration or a tax stamp for suppressors. It transfers on a Form 4473 with a background check through a Class 3 (SOT) dealer. State and local laws still apply.

Buy the Radical Defense CS3 Suppressor, .30 Caliber, Hub Mount

As of October 9, 2026, this suppressor transfers on a Form 4473 with a background check at your Class 3 (SOT) dealer, with no Form 4 or tax stamp; state and local laws still apply. Set it up on a .30 caliber rifle with a 5/8×24 muzzle and a KFM flash hider. Order through Radical Defense‘s silencers and suppressed firearms lineup and our Lubbock, Texas team will handle the transfer, and it ships fast to your Class 3 dealer.