A system and method for attaching a muzzle attachment to a firearm. The muzzle attachment has an attachment body that is defined by an inner surface having a bore along the central axis of the muzzle attachment. The attachment body may include a threaded portion extending a length along the inner surface configured to engage a threaded portion of the firearm. The attachment body includes a lock that is configurable from a retracted configuration to an extended configuration. In the extended configuration, the lock is configured to securely engage a recess of the firearm. By threading the muzzle attachment onto the firearm and engaging the lock with the recess, the muzzle attachment system resists removal of the muzzle attachment from the firearm. The muzzle attachment may include vents. The muzzle attachment system preferably is indexed relative to the firearm for proper operation of the muzzle attachment during engagement of the lock.