M2A1 .50 Caliber Ammo Can 12 Gauge Storage Trays

CLICK HERE If you're looking for 12ga storage trays for a standard M19A1 .30 cal ammo can!

CLICK HERE If you're looking for 12ga storage trays for a Cabela's Dry-Storage Ammo Box!

Some manufacturers sell their shells in boxes that are so awkward that you can't fit that many into a can.  Maybe you have a mixture of different shells all in different boxes that also don't fit nicely together.  Or maybe you just have a bunch of loose shells just thrown in like candy in a candy jar.  All are very inefficient and do not maximize the space in the ammo can.  Gross.

So now you're stuck in this conundrum of either having to buy more ammo cans with money you could be spending somewhere else (more ammo?) or NOT buying another ammo can and taking it out of the boxes and dumping it all in loose like, well, candy in a candy jar.  Or maybe you have to store the overflow ammo somewhere else.  All unacceptable options, IMO.

Well, if you're anything like me then you're kind of OCD about how you store your ammo.  I like mine organized and well protected so just dumping a bunch of loose ammo or storing it outside of cans is a non-starter for me.

So, to that end, I wanted to maximize the number of shells I could stand up in a M2A1 .50 Caliber Ammo Can before I had to resort to buying more ammo cans.  I remixed these trays from koosh's original tray design and now the trays have been split in half in order to fit the Prusa MK3S+ bed (210mm x 250mm).  A side effect from breaking them in half is now they are easier to hold with one hand and easier to put in/take out of the ammo can.

I exclusively use 2 ¾" shotshells in all of my shotguns and they are all not created equal.  Take a look at this picture of the 9 different brands of shotshell I have:

These are all in the 2 ¾" shell spec and they all vary in length.  The RIO is the tallest of the bunch at 63.20mm (2.49") which is 6.32mm (0.25") longer than the shortest one I have at 56.88mm (2.24")!  There are numerous different shell lengths in the 2 ¾" spec amongst manufacturers so keep in mind that this will affect how many you can get in the M2A1 Ammo Can.  So, by design, the trays can be mixed and matched depending upon your shell sizes.

The trays are are divided up into 3 types:

• A set of “A” trays (A1/A2 - top layer only)
  • A1 - Holds 28 Shells
  • A2 - Holds 24 Shells
  • The “A” trays are recessed in a bit further from the edges of the can compared to the “B” trays.  
    • This is to account for the wide lip on the inside of the ammo can lid (see pics above) that can actually prevent the lid from closing.  By recessing them in a bit it will allow the shells to avoid the lip and utilize all of the height inside the can.  Although, at the cost of fitting 13 less shells than the “B” trays.
• A set of “B” trays (B1/B2 per layer - bottom layers)
  • B1 - Holds 35 Shells
  • B2 - Holds 29 Shells 
  • There is a gap in the middle where the trays come together where you can drop an extra shell in.
• A set of “C” trays (C1/C2 per layer - top or bottom layers)
  • C1 - Holds 16 Shells Max (dependent upon shell length)
  • C2 - Holds 14 Shells Max (dependent upon shell length)
  • The “C” trays are 25mm high so you can lay a shell on it's side and it will still be under the edge allowing you to stack other trays on top.
  • Use the “C” trays when you cannot use the “A” trays.  In this scenario, you'll have space for two layers of “B” trays but not enough space to stand the shells in the “A” trays (see estimates below).

I did not have any 3" shotshells to test to see how much I could get in, but here is a rough idea of how many shells will fit:

• Shotshell ≤ 60mm (2.36")
  • 1 Layer of “A” Trays (52 Shells)
  • 2 Layers of “B” trays (130 Shells)
  • 60mm shell height is about as high as you can go with the 3 layers of the A1/A2 and B1/B2 tray combos.  As you get closer to 60mm the cover will still close but it may push down a bit on the shells.
• Shotshell > 60mm (2.36")  and ≤ 76.2mm (3")
  • 2 Layers of “B” trays (130 Shells)
  • 1-2 Layers of “C” trays (26-60 Shells max)
• Shotshell ≥ 76.2mm (3") - estimated
  • 2 Layers of “B” trays (130 Shells)

Ultimately, you'll have to find the best combination for you!

I've created print files using Generic PLA and PETG and uploaded the model and project files as well.  You also do not need any supports!  However, the trays do take some time to print.  I tried to reduce that time by cutting down on layer size and width, but I found 2mm is the lowest I could go on the base and the circular shell holders without sacrificing integrity and strength.  However, you will find that it is well worth it in the end.

I hope this can be useful for any fellow shotgun owners out there.   Also, if you have any issues then just shoot me a message.  Thanks!

Maximized fit to an ammo can plus multiple sizes.