NOT FOR THE FAINT OF HEART... OR UNTALENTED
Alright, as I said before, these are not actually pics, but i did make them to my standards, which i hope is good enough for you guys
Also, on request of You, if you are making a model with too much space in beween the reciever and the top of the gun to allow the parts to protrude an effective amount to be used, what you have to do is cut out a notch for the parts. This is easiest to plan for when you are drawing the schematic on the lumber. Simply place the parts relative to where they will be placed, and sketch a window for them to move freely. I would Highly reccomend capping off the notch at the top to decrease the amount of stress on the amount of wood that is remaining. See my MP5K or HK416 for an example. (I personally use the top rail to complete the connection)
Step 1: Buy Lumber
Step 2: Plane Lumber
Step 3: Find Gun Details/Dimensions and Print
PS: Use this site, its the one I use.