**This is an old design that I have not touched in years. It does work, but could be improved. If I get around to it sometime I may spend some time improving it.

I have gone through a couple revisions of this. The current version is rev3, which is making much better use of space and leaving a much smaller footprint. I also uploaded the .iges files so if anyone would like to modify them they can.

This is my try at a shotgun shell caddy, as used by many multi-gun competitors. This is not to be used for commercial purposes.

You will need:
8 - M4x20mm Machine Screws
8 - M4 Nuts
4 - 1/2"x 1/16" magnets (http://www.kjmagnetics.com/proddetail.asp?prod=D81-N52)
1 pack of rubber bumpers (http://www.mcmaster.com/#9310k12/=13rn8to)
1 TekLok mount (if that is what you want to use)
Super Glue

3D Printed Parts:
Material: ABS
One of each: 8_up_body, 8_up_front, 8_up_back
Layer Height: 0.2mm
Infill: 30%
Shell thickness: 1.0mm
Bottom/Top thickness: 1.0mm

Instructions:

Print the parts.
Press the M4 nuts into the slots, you may need to use a hammer and a punch to tap them in to place.
Glue the magnets into the 8_up_front part, allowing each one to dry before you put the next in, otherwise it can easily be pulled out by other magnets or metal parts.
Install the rubber bumpers by pulling the small ends through the holes in the 8_up_back part
Mount the 8_up_front and 8_up_back to the 8_up_body. You want the magnets and the fat ends of the rubber bumpers facing in (each side with the “shelf” for the shells to sit on). The 8_up_body will be oriented so that the side with the counter-bore slots is facing down.
You will likely need to adjust the ends so that it will hold the shells correctly.