I am rather curious if there's a separate, modeling tutorial for the weapons shown here. That AR15 made in Blender, I noticed, had some elements that stood out to me.
The M4 comes from this course by Jonathan Williamson https://cgcookie.com/archive/weapon-modeling-an-m4-rifle-in-blender/
All other weapons were either modeled by myself or Jonathan Lampel which don't have modeling courses.