Can I just ask my entirely reasonable question in peace?
Do you see the specs of the internal diameter of the flash hider on the Steger website and what calibers it supports? I sure don't.
Their website says they support the TRG21 and Remington 700 which have 308 variants.
Is the flash hider designed in a way where the muzzle side diameter is the same between models and only the diameter of the clamping mechanism changes?
If the SL8 variant isn't compatible then would the R700 or TRG21 option work? There's a lot of variability in those platforms so diameter is hard to determine.