How can I make the onTouched event more efficient?

Ok so I'm making a gun, and it fires bullets really fast, like at a velocity of 2000 or higher. And I have an onTouched function that damages a player when the bullet hits them, but I've been running into some trouble. Apparently, the onTouched event doesn't work 100% of the time, so if 10 bullets were to hit the player, only 5 or 6 would affect the player. I have a hunch that it's because the bullet is going too fast for the script to detect it. Any advice?

Guns that use moving bullets will always have that problem. It's recommended to use raycasting instead. There's a wiki article: http://wiki.roblox.com/index.php/Raycasting