After successfully 3D printing a high capacity magazine, Defense Distributed got back to work on perfecting its 3D printed AR lower. The first attempt failed after firing six shots, but the group was obviously not going to give up.

In a recent blog post, the group said it had “printed AR lowers figured out.” It also shared the following image:

As you can see, the AR lower looks pretty much the same as last time. The team presumably made some structural changes in the build, however, to make it stand up to the heat and pressure created by firing multiple rounds at once.

The new lower has exceeded expectations by staying intact and operational even after firing 600 rounds from an AR-15. Here’s the video:

The team hasn’t shared what it’s going to work on next, but a question posed on their blog indicates that the team may be working on making 3D printed magazines for more gun types.