Pretty cool.Fast-forward to 2019 and a decentralized collective of gun designers operating under the group name Deterrence Dispensed have perfected a method of producing DIY 9mm barrels which not only match but potentially can exceed the quality and performance of many professional factory produced barrels. The best thing about this method is that this allows you to produce barrels without needing a workshop and can even be made quietly in the comfort of ones cozy apartment. Along with a $200 Ender 3 3D printer, parts for this setup cost less than $100 and the process of making each barrel takes less than 30 minutes to complete. The tubing used to make the barrels can be ordered from Aliexpress and is supplied pre-hardened. Unlike challenges with traditional rifling methods, the ECM process is unaffected by the hardness of a material and can be used on any type of steel without needing to anneal or re-harden.