HW80 Barrel Query an oddity?

[copperjacket]

I have a 16” HW80k barrel that has both open sights and indeed is screw cut for a moderator. It is fitted with what looks like a DM80 muzzle brake.

Is the combination of fore sight and threading a factory option?

Many thanks

[Mach 1.5]

Seen the same set up on a HW30 and a HW77K a friend of mine imported from Germany so could well be a factory option but intend for our shores. Mach 1.5

[copperjacket]

Thank you very much. There is no importer stamp nor indeed serial number so that would make sense.