discs shot in air have very little resistance do to very little weight and no ground friction so is s moot point in regards to game animals unless your shooting ducks of course---shooting a moving deer will only have an eefect if ---example--arrow is penetrating front of lung and front leg is coming forward and meets it in stride as it is exiting, this can deflect and or break an arrow !!! without bone deflection their should be no loss of penetration