I see no issue running the halo on your gun as it sits. have you talked to GT about that f/hider?
The collar slips just behind the f/hider
Then tightens up on the hider and can.
Before & After
Gratuitous whats your dust cover say, pic
Precision measuring done on the fly, adapt and move on
I could limp out for my digital caliper if you need a better measurement.