Box for rifle ammunition that protects ballistic tips and does not rattle in the field.
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updated December 25, 2023

Description

PDF

Simple container that holds one box of rifle ammunition. There are standoffs in the bottom of the case to protect ballistic tips.

Print Settings

These are my settings but use whatever you want.

  • PETG
  • 0.4mm Nozzle
  • 0.2mm Layer Height
  • 3 wall/perimeters
  • 15% infill - There is very little area to infill, so it doesn't really matter.

You will need to use Fusion 360 to modify the parameters. Fusion 360 has a free hobbyist license, but they make it somewhat difficult to find the link. You should use google to find where they have hidden it.

Parameters

Once you've got the model open in Fusion 360 you can modify several parameters from the Modify →Change Parameters window.

CaseDiameter is the diameter of the brass near the primer end. You should add clearance to this number for easy shell removal. I use .010", but if you want them to need a little force to pull out  use less.

WallThickness is the thickness of your walls and floors. This should probably be a multiple of your nozzle width, so I used mm here. If you have belted rounds you may need thicker walls to allow for clearance.

TipSpacing is approximately how far up the standoffs that protect the ballistic tips are from the bottom of the case. If you have really pointy tips you may need to increase this.

BrassLength is the length of the brass. I  use this number to get an approximate height for the box walls. If you want your walls taller (less shell showing when the box is open) make this number bigger. My target was  ~0.5" of brass sticking up above the box wall, but you can do whatever you want.

LidDepth is measured after you print the Test Box. With the shell inserted into the Test Box measure from the bottom of the box to the top of the shell. This will ensure the box closes flush.

LidTolerance controls how tight the lid fits. I like mine to not fall open in the field, so I use 0.005". If you want a very easy sliding fit that will just fall open 0.010" works. Obviously this will also depend on your printer and print quality.

Test Parts

To save time and filament getting the fit just how you want it, the Fusion 360 File has a Test Parts component that you should use to tune your tolerances and dimensions. Enter all the parameters except LidDepth, which we will use later. Using the browser tree on the left side of the screen, find the Test Box body under the Test Parts component and right click it and select Save as Mesh to export an STL. Print this STL and check a few things:

  • Is the shell too tight or too lose? You might want to adjust CaseDiameter.
  • Does the balistic tip touch the bottom of the case? Put some paint on the ballistic tip and put it into to Test Box, if the paint transfers to the floor of the box you should adjust TipSpacing.
  • Is there enough of the shell sticking out for you to grab? Adjust BrassLength to change the height of the box.
  • Once you are happy with the above checks reprint the Test Box (if you made any changes) and measure the length of the shell and the box. This is the LidDepth you need to enter in Fusion 360 parameters.
  •  

Now export and print the Test Lid the same way the Test Box was printed.

  • Test fit the Test Lid on the Test Box and adjust LidTolerance and LidDepth as desired. Reprint Test Lid after any changes to verify fit.

 

Once you are happy with the fit of the test parts export the Box and Lid components from the browser tree and print your box. Might be a good idea to emboss some text with your slicer! 

Post a make and let me know how it went!

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Model origin

The author marked this model as their own original creation.

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