A locking system for a firearm attachment. The locking system having a rotating lock ring having a lock-and-release lever rotatably mounted thereto. The lock-and-release lever having a lock engagement surface optimally configured to forcefully engage a locking surface when in a locked orientation. The locking ring having a nonconcentric engagement surface that repositions in a radial direction when the locking ring rotates and the nonconcentric engagement surface is configured to engage the muzzle of a firearm for locking the muzzle attachment thereto.