Muzzle Brakes, threaded or welded

[45_acp]

Is it ok to have your muzzle brakes threaded on or do they need to be welded onto featureless ar's & ak's

[fusionstar]

They can be just threaded on if the barrel itself without the muzzle attachment is 16" and above. If its below 16" It must be permanently attached to become 16" and above.