Like all the player controlled scorestreaks, the bullets are very dependent on the connection. If you don't have a good host, trying to snipe with it sometimes works. People who don't bother to shoot things down help, too.
I usually get 0-3 kills a Dragonfire doing this.
You could also trying playing Hardcore KC. It kills in one to two bullets. Just keep it low, though. People tend to shoot things down very fast in HC.
What do you mean "snipe" with it? Zoom in?