Urutau (3D Printable Firearm)

The Urutau is a physible, 3D-printable, semi-automatic, bullpup, pistol-caliber carbine. The firearm was designed and manufactured between 2021 and 2024 by a gun designer known by the pseudonyms "Joseph The Parrot" and "Zé Carioca."

Urutau
Type	Semiautomatic carbine
Place of origin	Brazil
Production history
Designer	Zé Carioca of Deterrence Dispensed
Designed	2021–2024
Unit cost	$500 Upfront, $150 Thereafter
Produced	2024–present
Specifications
Mass	2,380 g (5 lb 4.0 oz) with empty magazine
Length	475 mm (18.7 in) to 660.4 mm (26.0 in)
Barrel length	250 mm (9.8 in) to 406.4 mm (16.0 in)
Cartridge	9×19mm
Action	Closed bolt blowback action
Feed system	CZ Scorpion Evo 3 Magazine, 3D-printed or professionally manufactured
Sights	Iron Sights

Etymology

The gun's name is a reference to the common potoo, also known as "The Ghost Bird."

Origin

The Urutau was originally designed between 2021 and 2024 by Zé Carioca, a pseudonymous Brazilian gun designer. The design was beta tested on the platforms of Deterrence Dispensed (also known as The Gatalog) and Are We Cool Yet? (AWCY), but at one point since the beta chatroom on AWCY? was a bit dead, Zé Carioca asked the guys there to move to the Gatalog chat room. AWCY distanced itself from the project a few weeks before its release due to unspecified reasons. The Urutau file package was published on August 20, 2024, under a CC0 1.0 Universal license.

Design

The design of the Urutau is inspired by previously published 3D-printable firearm designs, the Shuty AP-9 pistol by Derwood, the FGC-9 by JStark1809, and the Partisan 9 by ImmortalRevolt.While most of the underlying mechanics of The Urutau are comparable to the FGC-9, all parts were significantly redesigned. Compared to these designs, the Urutau sought to improve the ease of manufacture, invulnerability to state intervention, and competitiveness with modern standards. It achieves this by optimizing the ballistic efficiency of the 9x19mm Luger cartridge, eliminating the need to access and utilize welding equipment, minimizing dependence on firearm-associated components, minimizing steel drilling, minimizing felt recoil, enhancing the reliability of the fire control group, utilizing magazines comparable to the CZ Scorpion Evo 3's, enhancing mechanical safety and out-of-battery resistance, and enhancing the intuitive use of the design. As the Urutau is a bullpup, its minimum overall length is similar to if not an improvement to its predecessors. The Urutau is designed for a global audience. The design is made for metric fasteners and other hardware, though imperial design alternatives are available for those living where sourcing metric hardware is difficult. The magazine is 3D-printable, and the entire design works without needing any commonly regulated, commercial gun parts. The bolt carrier assembly, a stress-bearing component, is manufactured from steel bar stock and processed by sawing, drilling, filing, cleaning, and using adhesives to secure the steel parts to a plastic housing. The Urutau's barrel, another stress-bearing component, can be completed in several ways, but the recommended method involves electrochemical machining conducted on a piece of hydraulic tubing. With the exception of fasteners, pins, springs, and other widely available metal hardware, the rest of the Urutau is 3D-printed.

Modifications

The Urutau file package contains multiple alternative design approaches which include:

• A bolt carrier assembly which uses an M8 screw to secure the metal components to the plastic instead of using adhesives. This modification is intended to optionally enhance the ease of disassembly at the expense of a little more work up front.
• A firing pin made from a long M4 screw as an alternative to a screwdriver shaft. This modification is intended to enhance supply-chain resiliency and minimize the risk of correlation attacks. This modification requires access to a small lathe.
• A lower receiver, barrel cover, and trigger which use stainless steel pins and heatset threaded inserts as an alternative to threaded spacers. This modification is intended to enhance supply-chain resiliency and minimize the risk of correlation attacks.
• A safety switch designed to use magnets instead of plastic detents.
• Parts to optimize the design for left-handed shooters.
• A cutaway upper receiver for diagnostic purposes. (Firing the gun with a cutaway upper receiver is possible but dangerous and not recommended.)

Given the open-source nature and CC0 1.0 Universal license applied to the Urutau, many modifications to the original design have appeared online. Some of these modifications include modified grips and barrel covers.

A video trailer published before the Urutau's publication date teased at the design being select-fire or fully automatic. This feature was not included in the final release with it being semi-automatic only. The designer, Zé Carioca, explained that this was for a number of reasons. First, he noted that the select-fire design was unreliable given an issue with bolt-bounce and auto sear timing. Second, he noted that they were unable to test the select-fire design to Deterrence Dispensed (Gatalog) standards. Lastly, he noted that the documentation's author, RSmith28, refused to write documentation for a select-fire design due to ITAR concerns. As of the Urutau's publication, technical data for non-automatic and semi-automatic firearms were removed from the USML, the list of items controlled under ITAR, but fully automatic firearms and conversion devices thereof had not. It is anticipated that Zé Carioca will independently publish a select-fire variant of the Urutau once he resolves the bolt-bounce issue.

Documentation

The Urutau file package contained a collective total of about 200 pages of documentation, including instructions and other auxiliary documents. These documents were authored and illustrated by RSmith28, an affiliate of Deterrence Dispensed.

Primary Documentation

The primary documentation included in the Urutau's file package is 105 pages and conveyed the firearm's assembly instructions and other important information. It has 21 sections:

1. Title & Introductory Pages
2. Safety Advisory
3. American Legal Warning
4. OpSec & Obfuscation
5. Machines & Tools
6. Ammunition
7. Barrel
8. Materials
9. 3D Printed Parts
10. Bolt Carrier Assembly
11. Hammer Spring Winding
12. Lower Assembly
13. Rear Cap Assembly
14. Upper Assembly
15. Iron Sights
16. Magazine Assembly
17. Final Assembly
18. Function Testing
19. Maintenance
20. Troubleshooting
21. Technical Aspects and Design Choices

Of particular note, The Urutau's documentation is the first notable 3D-printed firearm to include advice for avoiding detection by law enforcement, as detailed in the OpSec & Obfuscation Section. West Midlands Police and the BBC’s show “Forensics: The Real CSI- Untraceable Firearms” are credited for inspiring or confirming the contents of the OpSec & Obfuscation Section by the authors. of Its advice included understanding the importance of secrecy, managing physical evidence, managing digital evidence, secure communication practices, avoiding or evading know-your-customer (KYC) requirements on retail websites, and finding activities to act as a cover for manufacturing a firearm.

Extended Length ECM Barrels

In the "ECM Barrel" directory of the Urutau's file package, a 67-page document titled "Extended Length ECM Barrels" is available. It is a comprehensive instruction manual to create a 9x19mm Luger barrel with a piece of hydraulic tubing and electrochemical machining (ECM). The guide contains contextual information, instructions on basic toolmaking, the electrochemical machining process itself, and post-processing. It has seven sections and a total of 12 subsections:

1. Warnings
2. Key Words & Definitions
3. Electrochemical Machining Fundamentals
4. Parts of a Barrel
5. Machinery, Tools, & Materials
   1. 3D Printed Parts
   2. Barrel Stock Preparation
   3. Fixture Creation
   4. Boring & Chambering Rod Creation
   5. Rifling Mandrel Creation
6. The ECM Process
   1. Rservoir & Pump Setup
   2. Boring Process
   3. Rifling Process
   4. Throating & Chambering Process
7. Post Processing
   1. Shaft Collar Fitting
   2. Headspacing
   3. Chamber Honing

Although manufacturing or having access to a barrel is integral to manufacturing an Urutau, RSmith28 specified that "we chose to compile [this document] separately, as its contents will likely benefit more than just the Urutau."

John Smith Practices Good OpSec!

In the "Mods & Extras" directory of the Urutau's file package, a seven-page document titled, "John Smith Practices Good OpSec!" is available. It is referenced at the end of the OpSec & Obfuscation section of the Urutau's documentation as "a general example of purchasing and shipping a product without leaving a digital paper trail."

This document is formatted like a story book, adorned with AI-generated artwork. It tells a fictitious story of a man named John Smith who desired to build an Urutau in an area where gun laws were prohibitive. To acquire the materials for the Urutau while avoiding surveillance, he purchases a gift card for a retail website with physical currency from a local convenience store. He then places the order from a publicly-available computer and ships the goods to an apartment building with an unlocked mailroom. After acquiring the goods, he builds his Urutau and the story concludes.

The New Second Amendment

At the root directory of the Urutau's file package, a nine-page document titled "The New Second Amendment" is available. This document is formatted as an open letter to The Urutau Builder. It is broken into three sections.

The first section is titled, "The Triple Constraint." It begins by making a thesis that the ideal privately manufacturable firearm design will meet three design objectives. They are:

• Practicality of Manufacturing Processes
• Invulnerability to State Intervention
• Competitiveness with Modern Standards.

The section goes on to argue that these three design objectives form a triple constraint, providing three examples of firearms that only meet two of the three design objectives.

• Firearms manufactured with factory equipment, citing that they are impractical for most people to manufacture.
• Firearms manufactured with part kits, citing that they are vulnerable to state intervention and of little utility outside the United States of America.
• Improvised firearms, citing that they are not competitive with modern standards.

The second section is tilted, "The New Second Amendment." It begins by expressing concern that either through legislative action or the eventual collapse of the United States of America, The Second Amendment to the United States Constitution is vulnerable. The section also expresses concern that the Second Amendment is limited and "has national boundaries."

To counteract these concerns, the document seeks to establish a principal encapsulated in "The New Second Amendment," reading:

"To permanently undermine global firearm prohibition, the rights of all people to keep and bear arms must not be possible to infringe upon."

This statement, a broad idea and written to mimic the Second Amendment, is expounded upon. The document explains that the availability of privately manufacturable firearm designs which meet the three design objectives will establish The New Second Amendment.

The section concludes by providing ideas for how the reader can perpetuate The New Second Amendment, which include:

• Building an Urutau or any other weapon which meets the three design objectives.
• Beta testing weapons which meet the three design objectives.
• Learning how to use CAD (Computer-Aided Design) software.
• Developing new manufacturing techniques and uses of technology.

The final section is titled, "The Perpetual Distractions." It explains that it is intended to counsel the reader in avoiding distractions they may encounter when perpetuating The New Second Amendment. Its advice includes:

• Maintain a Global Perspective
• Practice the Free and Open Source Ethos
• Assign Social Capital from Hard Work

Without starting a new section, the document offers a concluding paragraph which states that the reader will experience adversity as they perpetuate The New Second Amendment, but their adverse experiences will make them more virtuous.

Alternative Design Choices

The Urutau file package includes a directory titled "Mods & Extras" which includes alternative options for building the Urutau. (See Modifications.) Each modification includes a PDF or TXT file explaining how to utilize it. The directory also includes a standalone copy of OpSec & Obfuscation and a Spanish translation of The New Second Amendment.

Availability

The Urutau file package was originally published on Odysee, a free-speech blockchain based video, audio and file hosting site using the LBRY protocol. Zé Carioca asked the Odysee user PLA.Boi to host the files initially as there was a delay in getting Deterrence Dispensed/The Gatalog to publish the files. After a few days, Deterrence Dispensed started hosting the files under their Hybrid Designs Odysee page. While this is the official place The Urutau is hosted, it is available from other Odysee users and other parts of the internet. The files are also available on DEFCAD, though unlike on Odysee, they are locked behind a paywall.

See also

• List of notable 3D-printed weapons and parts
• Privately made firearm

External links

• Urutau and Manual on Odysee