Finally finished instructions for this fully automatic Lego R99. Link in comments. : r/apexlegends
Lego Guns - Instructables
Build your own working LEGO Nerf gun!
Lego Gun Tutorial - 01/2022
Elite Weapons for LEGO Fanatics: Build Working Handcuffs, Body Armor, Batons, Sunglasses, and the World's Hardest Hitting Brick Guns: Amazon.co.uk: Hüdepohl, Martin: 9781632205063: Books
Review - The BrickGun Book - Jeff Boen - BrickNerd - All things LEGO and the LEGO fan community