Stopping Power - Call of Duty: Modern Warfare 2 wiki

Stopping Power increases every bullet's damage by 40%. For most weapons, this is the equivilent of taking one less bullet to kill the enemy.

Challenges

• Stopping Power Pro I: Kill 30 players using the perk. 
• Stopping Power Pro II: Kill 60 players using the perk. 
• Stopping Power Pro III: Kill 120 players using the perk. 
• Stopping Power Pro IV: Kill 250 players using the perk. 
• Stopping Power Pro V: Kill 500 players using the perk. 
• Stopping Power Pro VI: Kill 1,000 players using the perk. 

Pro Version

Increases the damage against enemy vehicles, such as Chopper Gunners and Pavelows. The Pro version of Stopping Power is basically useless because enemy vehicles will still attack the player.

Tips

• Its the most commonly used Tier 2 perk because it's the most effective. Stopping Power takes effect on every shot you fire, while other Tier 2 perks are situationlly specific.
• Although your first instinct may be to use Stopping Power on every class, check if the weapon requires it. Many weapons, such as the AK-47 and TAR-21, do not require the use of Stopping Power.