Buffalo Bore Heavy 40 S&W 155gr Centerfire Ammo - 20 Rounds - Buffalo Bore's Heavy 40 S&W +P load uses flash suppressed powder that gives high velocities at low pressures for a potentially life saving advantage. More than 90 percent of all human shootings in the USA happen in low light, and you don't want to be blind after you fire one shot in a life threatening, high stress situation.