The SureFire RC2 has a diameter of 1.5". The Midwest Industries 12.65in Combat Rail T-Series One Piece Free Float Handguard has an internal diameter of 1.3" so that suppressor will fit inside this Midwest Industries 12.65in Combat Rail T-Series One Piece Free Float Handguard.
The Combat Rail T-Series is designed for use with Mil-Spec forged AR-15 upper receivers. If the RF-15 fits those criteria, then yes.
The Midwest Industries 12.65in Combat Rail T-Series One Piece Free Float Handguard will work with the Ruger AR556 with the free float handguard.
i cannot confirm it as i have not seen one of these rifles in person to test with. your receiver threads need to be 1-1/4"-18 pitch and the area right under the picatinny rail above the barrel must be less than .650" and at least .5" tall from the bottom of the pic rail
you will need to go longer. 12.625 will end at the start of the gas block leaving the gas block exposed. if your gas block is pinned this is not an issue if it is set screwed, regardless of dimpling, i would recommend a longer rail.
yes. ////
yes this should fit behind a A2 front sight base
no this is our CRT combat rail T-series
No, this is AR15. It will not fit an AR-308.