DEFCAD Newsletter - Printable AR22 Designs
July 18, 2022
Welcome to another special issue of the DEFCAD newsletter. From time to time we step back from the newest designs in guncad and instead survey a particular sort of printed firearm.
Today’s issue reviews the many printed AR-22 firearms. In the context of guncad, an AR-22 firearm is any platform that uses a “conversion bolt” such as the CMMG Bravo, Atchisson or Ciener bolts to fire .22 rounds in semiauto. Often these bolts are the only firearms part in the entire platform. Read on to learn more!
The earliest AR-22 designs that we are aware of were both released by Deterrence Dispensed, and are both, unlike the following platforms, traditional lower receiver designs. The first of these, the FMDA .22LR Lower, was developed by the venerable FreeMenDontAsk in 2019; the DS1913 lower by nguyenkvvn was published almost exactly a year later. Both are still considered to be quality releases even many years later.
The second generation of guncad started in 2019 and in that year there was nobody more prolific than FMDA. His designs at the time were generally frames and lowers patterned after their aftermarket designs, either matching their dimensions exactly or with minimal changes to make them viable as printed firearms. The .22LR Lower Receiver is precisely this sort of design. The included documentation does not mention provenance, so this design was likely either modeled from scratch, or from an earlier FOSSCAD AR lower design such as the AR-15 v5.
The DS1913 by nguyenkvvn has a clearer history - it is expressly credited to the earlier Disruptive Solutions design. This design was thoroughly refined and tested for 3D printing - its name comes from the fact that the buffer tower was filled in and used to mount a small 1913 rail to which a stock or brace can be attached. The same developer also designed and released the Daichi .22LR printable upper receiver, which is the earliest functional printable upper that we are aware of.
The SG22 by Booligan is a hybrid design, requiring only the CMMG BCG and barrel, with all other parts being printable. This was the first hybrid AR-22 designs to achieve widespread popularity, and despite being over a year old the SG22 is still widely printed, being considered an easy first project for new printers. Its spiritual predecessor is the Goldblum-22 which, though a parts kit replacement instead of a hybrid, still contains similar aesthetics to the SG22 proper.
The SG22’s enduring popularity can be attributed to many qualities - the durability of its design, its ease of assembly, or its thorough documentation come to mind - but in truth I believe the main driver is, like Booligan’s other design, its fantastic sci-fi aesthetics (the SG stands, of course, for Space Gat).
This platform serves as an inflection point in AR-22 designs - prior to its publication, all AR-22 designs were parts kit conversions that mostly stuck to the tried-and-true aftermarket AR-22 aesthetics. The Goldblum-22 is a notable exception that proves the rule - its aesthetics are unique, but upon examination it was still, in the end, a lower and handguard. Following the SG22’s publication, however, virtually all other AR-22 designs have explored wildly different looks and feels.
The Tubee-22 from AWCY is a full firearm, but it started its life as an attempt to build a printed barrel body into which a steel barrel liner could be epoxied. Following the success of this, the rest of the gun was modeled out to prove the concept. It uses a Hellfire-style AR-15 lower and custom printed upper, meaning that the only required firearm part is a CMMG Bravo bolt.
The Tubee-22 was released in 2021 as part of a flurry of AWCY .22 releases. Prior to its release, barrel liners were not as commonly seen in printed firearms - while the technique of reinforcing 100% printed designs with steel tubes was not unknown, these were often smooth pipe instead of chambered and rifled liners.
Following this release the idea of using rifled liners has spread throughout the community and has appeared in many other designs. It is also interesting to note that the Tubee barrel design has itself been spiritually succeeded by the Proto Barrel, which replaces the filament-intensive solid printed barrel body with lightweight carbon fiber tubing. The goal of the printed barrel body is to protect the liner and keep it straight, and both these designs do so admirably.
The ScARpion-22 by AWCY’s cursd is an AR-22 chassis made to look like the famous Scorpion EVO. The design is quite flexible and can be made with several different AR-22 bolts and barrels; it also contains multiple handguards, braces and more. The designer later released a “2055” furniture pack for further modification.
Despite the ScARpion’s name, it does not actually use any Scorpion EVO parts - it simply is made to look like one. The ScARpion design allows for the use of parts from many different manufacturers, to fit what you have on hand or what you are able to find. It works with CMMG, Atchisson and Ciener bolts among others, and with AR-22, 5.56 or Tubee-22 barrels. This is all described in the included documentation.
The 2055 furniture pack, also by cursd, contains a variety of handguns, grips, carry handles and other accessories to further modify the futuristic Scorpion aesthetics. Also of interest for the ScARpion is a DIY bolt design by HulkHoganHH. As with all DIY bolt designs, use caution with this design, and consider proofing it on low velocity rounds.
First covered in our June 21st, 2021 newsletter, the Trident from Mussy and zer0fux is one of the most recently released AR-22 designs. Using an AR-22 bolt, this platform is designed to be the most compact foldable gun possible - the stock can of course be folded against the body, but this design also allows the barrel to be released from the upper and folded against the body as well!
The only firearms parts required for the Trident is an AR-22 conversion bolt (either CMMG or RTB 556). Parts from an AR-15 FCG are required as well, but these of course can be printed if desired. The barrel for the Trident is a Tubee-22-like solid barrel body into which a liner is epoxied - in fact, this solid barrel contains large outer threads that are critical to the withdrawal operation to allow the barrel to be folded.
Good documentation is included that shows how to assemble the firearm - not just text documentation, but videos demonstrating assembly as well. This is a good practice which we would like to see more of!
Our final design is from Black Cat Aircraft & Manufacturing (aka AG Off Grid). Released in late 2021, this is a printable lower and buffer tower meant to be used with a CMMG Bravo bolt and aftermarket AR-15 upper receiver.
Requiring only two printed parts which are screwed or epoxied together, this is a relatively lightweight design, but lightweight is okay for the relatively light .22LR round. The author suggests that this should only be used for plinking - but, of course, that is the whole point of all these AR-22 designs, to some degree. In any case, this is likely a good design for someone who wants a slightly more standard AR-22, but with nontraditional aesthetics.
An AR-22 platform is often a great first guncad project - the use of a drop-in conversion bolt and the lower power of the .22 round makes building these both easy and particularly safe. Pair one of these with a printable AR-22 magazine for maximum guncad fun!
We are happy to note that this issue marks the one-year anniversary of the DEFCAD newsletter. Thank you to those who read this regularly and share this newsletter with others, and we look forward to continuing to organize and share information about the world of guncad. Acta Exitum Probant.