Wow, third gun in a row! I'm not really satisfied with the quality of this model. I blame it on the concept, which did not display details very well and only showed it from one angle. I hope that the Hard Surface Modeling Course by Gleb Alexandrov and Aidy Burrows will improve my skills enough to remake this gun.
Oh, I forgot to mention that this was my last Blender 2.79 project. From now on, I'll be working in Blender 2.8.
@jlampel Thanks! I worked on it for quite a long time. I lost count, but it was probably weeks. That taught me a big lesson, which was: If something is going to take weeks, start another project to work on along with the really big project.
This looks to be your best model so far, nice progress!