DEFCAD Newsletter - Professor Parabellum 100% DIY Designs

June 08, 2022

Welcome once again to the latest issue of the DEFCAD newsletter. Today’s issue is focused on one of the founding developers of DIY guncad: Professor Parabellum.

The good Professor began creating and releasing guides and plans for the development of homemade firearms years before the guncad community as we know it existed, and he remains active to this day, still turning out new designs. All of his designs are 100% DIY, requiring no firearms parts, and as such these designs are ideal for home gunmakers outside of the US.

DEFCAD is proud to feature the full catalog of the Professor’s work. This work is highlighted below.


Practical Scrap Metal Small Arms

The earliest available work we have from Professor Parabellum is his Practical Scrap Metal Small Arms series, a 25-volume collection of blueprints and guides for building various firearms designs solely from hardware store components.

These designs include pistols, derringers, revolvers, submachine guns and shotguns. Many of these designs utilize laminated (stacked) flat steel shapes, and as the volumes progress we begin to see increasingly sophisticated construction techniques. Since their release these designs have been built in countries across the globe, proving their universal accessibility. DEFCAD features an individual page for each one.

Full Auto Hybrids

In 2020 Professor Parabellum began introducing “hybrid” designs that utilize printed parts where possible, and metal where necessary. Some of the first hybrid designs he released were full-auto SMGs that used uppers made from square tubing - both the Hybrid Square Tube SMG and the Cheetah-9 are examples of these.

The Cheetah-9 design adopts a custom-designed printed lower and an upper and bolt constructed from square tubing. It uses (along with all modern Professor Parabellum designs) an ECM barrel. The Hybrid Square Tube SMG also uses an ECM barrel, as well as a printed lower derived from the AP9 / FGC-9. Both of these take Glock magazines (including printed Menendez or DMB magazines) and both designs are open-bolt, full-auto only.

Semi-Auto Hybrids

Following his early full-auto-only hybrid designs, Professor Parabellum developed several fully DIY semi-auto designs that generally use a printed lower and a metal upper derived from round tubing. These include the DIY AR9, the Paralog and most recently the STRUG.

All three of these designs use ECM barrels. The DIY AR9, as the name implies, uses a printed AR-style lower; the upper for this design uses a steel pipe sleeved inside an AR-style upper. This design uses Glock magazines.

The Paralog uses a bare metal round upper mated to a printed lower derived from the SVTR. As such it utilizes either surplus or printed Sten magazines. The DIY bolt for this design somewhat resembles the MAC-11 style bolt on which it is based - full fabrication data is provided.

At time of writing the most recently released Professor Parabellum design is the STRUG, which returns to using a printed AP9 / FGC-9-style lower mated to a round metal upper receiver. The design uses a large DIY bolt which allows for a highly compact bufferless design. Given that the printed lower is derived from the AP9, this of course takes Glock magazines!

DIY Replicas

Aside from fully custom designs, Professor Parabellum has also created a few designs that derive aesthetics or architecture from existing commercial designs. At this time this includes a DIY Deer Gun and the fully DIY TC-10P.

The famous Deer Gun, developed by the US for use in Vietnam, is conceptually equivalent to the WWII-era Liberator. Professor Parabellum has made a version of this firearm using a drilled-out bolt as a barrel. This single-shot design can be chambered in several different calibers, including “Improvised Ammunition”, another Professor Parabellum-designed concept first described in Practical Scrap Metal Small Arms Volume 21.

The TC-10P shares a name with, and is based off of, an Enfield Arms design from the 1990s. The construction of this pistol is interestingly simple - the DIY metal internals are encased in a printed two-piece clamshell; the two halves are bolted together to secure everything in place. This design uses a slightly modified printable Sten magazine, also included.

Professor Parabellum is one of many homemade arms designers from the pre-guncad era who would release their designs via blueprints and PDFs - other designers include P.A. Luty, the author of the famous Expedient Homemade Firearms series, along with several designs from the now-defunct Paladin Press.

To my knowledge, of all these designers only Professor Parabellum remains active, having made the jump into using modern fabrication techniques. Let us offer thanks to him for his amazing work! I encourage all readers to check out these, and many other designs, on DEFCAD.

Ghost Gunner 3s, GG3s, True Desktop CNC, by Defense Distributed Ghost Gunner 3s, GG3s, True Desktop CNC, by Defense Distributed

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