Forbes has published an article about some of the modifications and upgrades that the 3D printing community have made to the open source DefCad Liberator Pistol. Andy Greenberg writes …

Travis Lerol, a 30-year-old former military software engineer in Glen Burnie, Maryland, printed his Liberator (shown at right) within days of its appearing online. Unlike the original printed gun, he says he’s altered his to have a rifled barrel, a move designed to avoid the National Firearms Act, which regulates improvised and altered weapons and has a provision covering “smooth-bored” pistols. He’s also built another version of the barrel for .22 ammunition that uses a metal insert for reinforcement, instead of the entirely-plastic barrel for .380 rounds used in Defense Distributed’s original. And he’s cast versions of the Liberator’s barrel in epoxy that take .380 and .45 ammunition, a design he argues will be more durable than the pure ABS plastic Defense Distributed tested.

The ability to experiment with open source 3D printed designs is powerful. Just like with open source software, designs like the Liberator can evolve keeping the best features and community modification,  while bad ideas fall by the wayside.