Bone Rush inflicts damage, hitting the target 2-5 times per use. There is a 33.3% chance that it will hit 2 times, a 33.3% chance that it will hit 3 times, a 16.7% chance that it will hit 4 times, and a 16.7% chance that it will hit 5 times. Ignoring the possibility of missing, it will hit 3.168 times on average, giving it an average power of 79.2.
If a Focus Sash, Focus Band, or Sturdy activates before the last strike is dealt, the following strike will cause the defending Pokémon to faint. A Focus Band can still activate repeatedly to prevent fainting, but each chance is independent of the previous one.
Bide and Counter will only acknowledge the last strike of this move.