In this tutorial, I show you how to make a gun in blender 2.6. If you got problems, just comment!
! Edit: A lot of people miss the “Limit selection to visible” part, resulting in selection problems later on. If you try to select a part of the model, but then find later on that it only selected the front part (the part you were looking at, not everything behind it), that means you didn’t uncheck the “Limit selection to visible”-button. You can find it here: http://i.imgur.com/8Zd0Q3l.jpg