Serbu Developing a 20mm Bolt Gun: the Typhon 20 (VIDEO)

Serbu, manufacturer of the compact and niche Super Shorty AOW shotgun is working on another project build around the Navy’s M21A1 round. The result is a bolt-action single-shot 20x110mm rifle that exists, well, just because.

Development started more than ten years ago when the Navy was supplying developers with the 20mm Hispano cartridge, which is primarily an aircraft and anti-aircraft cartridge. Mike Serbu of Serbu Firearms jumped on the opportunity to make something that would absolutely trounce the 50 BMG rifles he was working on, and decided that this was the way to go.

Except duty called and Serbu scrapped the project, and put his work to-date into mothballs, untill just a few weeks ago. Serbu unpacked the Typhon 20 and put it back in pipe.

The Typhon 20, in its current configuration, is not a “sporting” arm by ATF standards. Chambered in the tremendous 20x110mm cartridge, there is little game or sporting purpose to match this gun. But that’s only for now. The Typhon 20 is a flexible gun with a modular bolt head that can be swapped for other cartridges, including .50 BMG, and with a matching barrel, can be sold on the open market.

This opens doors for the Typhon 20, making it a gun someone can buy in an accessible format and later install a different bolt face and barrel, after jumping through the correct hoops.

Also, due to the extremely short supply of 20x110mm cartridges, Serbu plans to chamber the finished Typhon 20 for the same 20x102mm ammunition used in Vulcan rotary cannons which should be easier to come by.

Still in the prototyping phase, the Typhon 20 doesn’t even have real furniture yet, and final specifications are a ways off. Final versions are expected to have less overbuilt barrels and a muzzle brake to deal with the recoil. “As far as the design it’s basically a scaled up BFG-50. I did the bolt handle differently, mainly because I hate machining that big ‘L’ shaped bolt handle track on the BFG,” said Mark Serbu, over at the Firearm Blog.

“Another thing I changed was to make the primary extraction cam a lot less radical on the Typhon, and fortunately it works great! Sometimes you’ll get an overpressured round on the BFG-50 and when you lift the bolt handle to the point where it hits the primary extraction cam you have to really beat on the bolt handle to get the case to unstick. Not so on the Typhon; as you can see on the video, extraction is effortless and the action is very smooth.”

With more time on his hands, Serbu expects a lot to come from this project. “I’m very happy with the gun! Future plans include actually producing the Typhon for sale (complete guns as well as receivers), and I intend to make a belt-fed, full-auto gun in this caliber too. That should be a blast…”

For more information on the Typhon 20, check out Serbu’s YouTube channel.

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