AR-15 templates
grabcad
Here are a few online templates I stumbled upon, but they don't include 3D options.
Download Model from grabcad
With this file you will be able to print AR-15 templates with your 3D printer. Click on the button and save the file on your computer to work, edit or customize your design. You can also find more 3D designs for printers on AR-15 templates.