Requires power (RF/FE) and specialized machines like the Reaction Chamber or Fabricator to craft high-tier gear. How to Install Gun Mods for 1.16.5

Often considered the spiritual successor in terms of animation quality and weapon variety for 1.16.5.

Minecraft 1.12. Techguns 1.12.2-2.0.2.0_pre3.2. 1.12.2. Forge. May 16, 2020. Techguns 1.12.2-2.0.2.0_pre3.1. 1.12.2. May 30, 2019. CurseForge

If you are looking for that specific "Techguns feel"—high-tech weaponry, 3D models, and complex machinery—these mods are the best substitutes currently available for 1.16.5: