Hoffman Tactical SL-15 v4.8


Hoffman Tactical SL-15 v4.8 STL Files

Version 4.8 of Hoffman Tactical’s AR15 Lower Receiver

Hoffman Tactical SL-15 Details

True works of art are never fully completed, and this release is no different. The SL-15, the flagship of the AR pattern lowers offered by Hoffman Tactical has seen another round of revisions since the second generation of this design, version 3.1, and with it have come a heap of changes and improvements that have the community very excited.

Hoffman Tactical is a pioneer of GunCAD design and engineering, responsible for landmark releases like the Orca, the SL-308, and the Super Safety. Now a household name in the GunCAD world, this developer is one to keep a close eye on if you want to be on the bleeding edge of research and development.

Hoffman Tactical SL-15 In The Wild



Video Credit: Hoffman Tactical (YouTube)

Hoffman Tactical SL-15 Tech Specs

First things first: what’s new with v4.8?

The third generation of the SL-15 features a number of improvements, including removing overhang rules in the trigger guard area and in the new integrated grip, both of which provide better ergonomics. The new lower also features improved overhang rules in other areas, such as the buffer threads. Built-in supports are now a thing of the past for the SL-15, as Hoffman Tactical has indicated confidence in the organic and tree supports generated by current-gen slicing software, and has instead opted to include support enforcer files. Split releases for developers have also been done away with in this release, meaning STEP and SolidWorks Part files are now packaged alongside STLs in one download for ease of access.

What about the rest of it?

The files are designed to accommodate PLA+ as a minimum, though documentation supplied by Hoffman Tactical recommends high-temperature Nylons and other filled materials for long-term prints. Durability may vary depending on selected printing materials.

The design is meant to support any standard AR-15 pattern upper as well as a standard AR-15 lower parts kit. Hoffman Tactical also recommends the use of their SL-15 Reinforcement Kit to further secure the lower in specific areas of concern.

Included in the download is both the full documentation and a short readme.

Required Parts for the Hoffman Tactical SL-15


  • Filament
  • 3D Printer
  • Complete AR-15 upper
  • Complete AR-15 lower parts kit
  • Mil-spec Carbine buffer


  • 2 – 10-32 x 1.25 cap head screws
  • 2 – 10-32 hex nuts
  • 1 – 10-32 x 3/16 set screw
  • 1 – SAE size 24 worm drive hose clamp


  • Punch set
  • Armorer’s hammer
  • Screwdrivers
  • Drill and drill bits
  • AR-15 castle nut wrench
  • File
  • Pliers


Documentation recommends the following filaments:

  • Polymaker PLA Pro / Any good PLA+
  • COEX Glass Fiber Nylon
  • Polymaker PA6-CF
  • Bambu PET-CF
  • Ninjatek Ninjaflex TPU / Any other TPU with 85A Shore hardness rating

The Hoffman Tactical SL-15 is a time-tested design that only gets better with each iteration, and is well-suited for builders of all skill levels.

Looking to get a hold of one of the most iconic releases in GunCAD? Download and build one today!

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Kem Regik
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