This design is based on the MK1 in professor parabellums book "Do-It-Yourself FULL AUTO ASSAULT SHOTGUN construction plans". This design is missing some obvious features that make it non functional in its current state. I also use Jay McMullan's 12 Gauge shotgun shell in this model so be sure to check him out. The design has heavy inspiration to the AA12 prototype down to the 1.4kg bolt mass (This design is really heavy). This design gets a 4.5/5 on my arbitrary DIY scale. This design needs minimal welding its mostly cutting tube to size and using a disk grinder to remove material on the bolt body. The receiver tube is very forgiving, but I would not cut the charging handle slot before you make the corresponding hole in the bolt. Should I work on a mag for this or does anyone care? Also a thank you to Jacob Devereux for your words of encouragement! Go to his grabcad and check out his 3d printable derringer.

This is a ppsh-41 bolt and chambered barrel that I have been working on. This bolt and barrel is from the sub machine gun designers handbook. This model also has some measurements corrected from a real ppsh bolt. The barrel is chambered 7.62 tokarev and is rifled with a similar rifling profile to that of the ak. The barrel also requires feed geometry to be cut into the chamber. I can also render a barrel in 9x19 if anyone is interested in this as it will feed out of modified tok magazines. I am currently working on the rest of the gun so I will likely post the complete model when I feed it is good enough to publish.