This mod adds in a 9mm homemade SMG. It comes with unique static and sound entries, as well as having it added to the appropriate perk lists, holdout lists, repair lists and weapon lists.
It can be found on Doc Mitchell's Sunset crate.
Also included is vendor leveled list integration (Chet, Johnson, Gun Runners, and a few others), as well as Fiend and Legion leveled lists integration. You can also build the SMG as a recipe at the workbench.