Hollow Reamer
grabcad
I've got a hollow reamer specifically designed for use on ordnance that might be worth sharing, even if the model itself isn't particularly exciting - if you're interested, feel free to either grab it from this thread or shoot me an email and I'll send it your way.
Download Model from grabcad
With this file you will be able to print Hollow Reamer 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 Hollow Reamer.