Received my (2) AK47 Smith Enterprises Vortex FH's today. Looks mean ass on a SA M7. The other is for my Polish UF. The FH does not have a detent lock. It is the standard self tightening configuration, 14x1. Smith is only making a few for the civilian market. Talked to him last week. The rest are for SF. Have not shot it yet. If you want one or two or....order soon!