Questions on new Sako/Tikka muzzle break for my T3 Tac

[davee]

I just received a muzzle break that I'd ordered 19 months ago when purchasing my Tikka T3 Tactical. There is a flat area with a slotted head screw that I am not sure what the purpose is. This screw stops before breaking into the threads on the inside of the break. I did not force it further than a medium heavy twist on the screwdriver. When stopped at full insertion, the head remains proud of the flat surface on the outside.

There is also a socket head cap screw that tightens the break in final position once it is threaded onto the barrel.
Also, should the flat be positioned at 6 o'clock or 12 o'clock, the answer to the purpose will likely determine the answer to question #2).

3 pics attached.

Thanks for any guidance.

 

[SHERMY]

The flat with the slotted screw should be at 12 o'clock.
The screw is for one end of a elastic mirage band, the other end attaches to a hook on a Sako scope base.