My journey with @pz3's M4 SOPMOD pack has been fun. A lot of what I've done is based on mid-2000s Delta Force MRE M4 setups.
Various model tweaks (mostly to add detail, some proportion corrections)
Receiver has a lot of added geometry, and is now configured with the selector on semi and dust cover open
Crane LMT stock corrections
Rail Cover corrections
New accessories
Schmidt & Bender 1.1-4x Shortdot
Rear Iron Sight (foldable)
Risers for optics
KAC MRE extended handguard (CENTCOM has one, but no .max file so had to make my own)
Rubber buttpad for the normal stock
RediMag attachment to hold an additional magazine
Gangster grip (A2 pistol grip attached to a light and with some buttons on it)
Plan on including some ready-to-play models and of course the .max files for making your own setups.