DR >= B#: MG breaks after use. Flip counter.
DR >= X#: FT eliminated after use. DC eliminated with no effect
Is this DR an original DR or a Final DR. i.e. If I use my MG against an enemy in a stone building (TEM +3) and I roll a 10 will the MG break? I have been playing that for B or X the original DR had to be greater or equal to the SW B# or X#, i.e. only on a roll of 12 (no matter the target) will the MG break.