Disassembly and overview - https://youtu.be/OiqfTG2oF4s Shooting the lego lower (name subject to change), an AR15 lower receiver made primarily of lego and, as far as I'm aware, the world's first lego firearm. It was completed using only hand tools and no measurement implements. It's had roughly 400 rounds through it with no signs of failure so far. ... https://www.youtube.com/watch?v=Z4KQZ0LJwuY

There is now a fully functional version - https://youtu.be/tTHFjao1nRo Second live fire test of the Block 19. I'm calling it a success. It functions fine when the magazine is held at exactly the perfect position, so I expect that it will start functioning consistently after the magazine catch is added. Since the last test, I've added the second pin to hold the rear of the locking block in place and addressed problems with trigger reset. The trigger had previously been failing to reset because the striker sear was sitting a hair too low relative to the rear rail. I was able to remedy this by applying a few layers of masking tape to the underside of the trigger mechanism housing. This isn't an actual fix, so much as a kludge to keep from scrapping the current frame. TODO magazine catch TODO slide lock (so that the slide stops flying off the frame) ... https://www.youtube.com/watch?v=BHz3dYdW2WY