50cal Ammo Can Organizer/Ammo Tray (MTM inspired)

Modeled after the MTM organizers; I got tired of cutting out the dividers for rifle rounds. Stacks with the MTM ones (and themselves) in cans, and will stack with each other outside of cans, but doesn't have feet to hold the alignment, so they can rotate and get misaligned if you're just stacking them on a shelf.

Fusion source file included for reference or modification; remixes welcome. Everything should be labeled, and it's fairly parametric, though I could probably move a few repeated dimensions to user parameters. It should be easy to rearrange dividers or change the height, to customize it as desired.

I usually print with 3mf, but I can include other formats (STEP, STL, etc.) if requested.

Capacity

Stacking alternating as pictured, the organizer tray holds:

30x 5.56mm rounds per layer in an assembled no-dividers one, and can fit 5 layers, for 150x in each half, or a total of 300x per tray. The top layer is a tight fit on the ends under the handle hinges, but it should fit flush, though it has a tendency to roll inward, pushing a round somewhere in the middle of the layer up. Combined with the top-level trays (4x of the 15-round trays, and one 40-round tray on top), it's a tight fit, but that gets you exactly 1,000x rounds per can, so you can easily tell approximately how many you have, and easy counting of bulk storage.
48x 9mm rounds in each compartment in an assembled 12-compartment one, for a total of 576x per tray. I usually just call it 1,500x per can when counting bulk storage.

Holds a decent amount of other calibers, but I haven't put .300 blackout or 12-gauge or other calibers into these printed ones to get exact counts yet. Should hold as much or slightly more than the MTM ones, since the walls are slightly thinner and the inside corners are square instead of filleted.

Printing

I modeled the organizer tray in 2 halves because it's too big for most printers. Uses filament for the hinge pins, and as "rivets" to hold the 2 halves together.

Only needs supports under the handle hinges and the one overlap overhang in the tray halves; tree supports worked fine for me. I printed mine at 0.28mm layers with generic PLA (I typically use Overture PLA+), and it feels about at strong as the injection-molded ones. Slicer estimate pictured for an A1, and it was about the same for an X1C; just over 2 hours with ~85g of filament per half+handle.

I had to take a knife and scrape off the underside of that overlap overhang to get the support artifacts off to ensure a smooth fitment, but that's probably dependent on your printer/slicer tuning.

I tested making the floor a hexagon mesh pattern, but that actually increased print time a good bit, so I left it solid.

Post Processing and Assembly

Tools required:

1/16" drill bit
5/64" or 2mm drill bit
Drill
Soldering Iron
Flush cutters
Pliers (probably needlenose)

For the handles, since the holes are printed vertically, you'll want to first drill out the holes in both the handle itself and the hinge-pin holes in the tray with the 5/64" drill bit, to be able to get a piece of filament in there easily. The middle hinge hole on the tray you'll have to do at an angle. There's a hole in the side of the tray that you can put the drill bit through; if you put the 5/64" drill bit as far out in the drill chuck as you can get it, it should be just long enough to get through the hinge hole.
Or if you want to modify the Fusion file to experiment with making the hole slightly bigger to avoid that step, note that that part of the design can be a little touchy.
I cut a piece of filament close in length, had to spin it while feeding it in, then flush-cut the ends off. It hasn't walked out for me, but optionally, you can use the soldering iron to melt/"weld" the ends to keep it from coming out, or leave a little filament sticking out of each end of the hinge, and melt the end to "peen" the end of the hinge pin, rather than melting the hinge pin and the hinge together.
The two halves are a snug fit, but they should go together. You might want to first scrape/cut any knobbly bits off the ends of the seams, depending on the printer tuning and finish quality. It can help to do these steps on a flat surface, like a countertop, to help keep the tray flat. Once they're fit together, you'll want to use the 1/16" drill bit to drill out the "rivet" holes. This will make it a nice tight fit for getting the rivets through both halves. You could use the 5/64" bit, but that may be hard to hold everything tight together while "peening"/"welding" the "rivets"/seams, since that'll be just a little loose.
Inserting the "rivet" filament into the holes is tricky and a little difficult, especially on the bottom holes. You'll definitely need pliers. It can help to "whittle" down the tip of the filament to make it angled. I start with the ones on the sides and middle, since they're easier, and then the bottom ones will stay lined up while you drill and insert those.
I usually drill out one hole, then put a piece of filament through, leaving some sticking out on both sides of the hole, to make sure nothing pops off while I do the other holes. Then I go to an opposite-corner hole, alternating between steps 2 and 3. I put the filament from outside it, being careful to watch the inside to make sure its not going to break or bend the inside of the overlap. It can help to put a finger directly over the inside of the hole, but you'll probably poke your finger when the filament pops through. It can also help to try to rotate the filament as you wiggle it in there.
After all the filament "rivets" are inserted, I pinch an overlap together and use the soldering iron to "weld" the top of the seam, to help hold it together while melting the rivets.
I cut one side of a rivet flush, and use the soldering iron to melt the end of the filament into the wall/floor of the tray. I usually just leave the iron as hot as it'll go, to ensure the filament thoroughly melts. You'll probably want some ventilation, to avoid inhaling plastic fumes. Be careful not to poke through. It can help to cut it slightly proud of flush, to leave you with some extra material to melt together. Then I do the same for the other side of that hole, then move to another hole.
I've tried to also "weld" the seams, but it's tricky and not pretty, and I don't think it's necessary for sufficient strength of the tray, unless you're putting something significantly heavier than 500x rounds of 9mm in it. I'd avoid doing it on the bottom face, so that it stays flat, since it's hard to keep a smooth surface with that.

Note that for the 12-compartment one, you won't be able to get to the inside of the rivets because of the middle divider, so I did the filament equivalent of TIG welding (using the soldering iron in one hand, filament strand in another, and melting the filament strand into the part) on the top edges and some of the seams around that on the inside, and it holds together fine.