Painting is generally done with basic, versatile, brushes. Sometimes however, you're better off using a custom brush to accomplish a specific end. In this video I showcase a brush pack designed to make the task of painting machine guns and muzzle flares easier. The brush pack is free, so feel free to download it!
And if you're intrigued by this concept of custom brushes, there's an entire Premium Series dedicated to it in the Ctrl+Paint store!