12 Gauge Ammo Box System (2-3/4") - Tight Packing, Stackable, with Latches & Ammo Can Packs

12 Gauge Shotshell Ammo Box System (2-3/4") Tight Packed Stacking • Print-in-Place Latches • Latchless Options • Dedicated Ammo Can Packs Standard cardboard shotshell boxes turn to mush as soon as they see moisture, spilling loose shells into the bottom of your range bag or dry box. I built this parametric 12 Gauge system to provide a durable, weather-resistant, and interlocking alternative for standard 2-3/4" (70mm) shells. How the Downloads Are Organized To keep the downloads tab manageable instead of scattering dozens of loose files everywhere: - Base STL Set (Direct Download): The standard 25-round hex field box (5 rows × 5 columns with latches) is uploaded directly as loose STL files (12_Gauge_2.75in_square_5rx5c_*). This holds one standard 25-round retail box of shells and is ready to slice immediately. - Configuration Zip Archives: All other layouts—including 25-round compact hex boxes, 100-round match flats, and the dedicated ammo can packs—are packaged as standalone .zip archives. Each archive contains the complete part set (box bodies, lids, latches, stacking rims, text plates, and bore hone) and is paired with a matching .png render preview.

Available Configurations ConfigurationGridCapacityPackingLid StyleIntended Use / FitmentDownload 25-Round Field Box (Base Set)5×525 ShellsSquarePrint-in-Place LatchesStandard 1-box field carrierLoose STLs + square_5rx5c_with_latches.zip 25-Round Field Box (Sleek)5×525 ShellsSquareLatchless SlideLow-profile / detent closuresquare_5rx5c_no_latches.zip 25-Round Compact5×525 ShellsHexPrint-in-Place LatchesCompact staggered carrierhex_5rx5c_with_latches.zip 25-Round Compact (Sleek)5×525 ShellsHexLatchless SlideCompact staggered carrierhex_5rx5c_no_latches.zip 40-Round Metal Can Pack4×1040 ShellsHexLatchless SlideUSGI .30 Cal (M19A1) Can12_Gauge_2.75in_hex_4rx10c.zip 63-Round Plastic Can Pack7×963 ShellsHexLatchless SlideHarbor Freight .30 Cal Can12_Gauge_2.75in_hex_7rx9c.zip 100-Round Bulk Flat10×10100 ShellsHexPrint-in-Place Latches4-Box Sporting Clays Flathex_10rx10c_with_latches.zip 100-Round Bulk Flat (Sleek)10×10100 ShellsHexLatchless Slide4-Box Sporting Clays Flathex_10rx10c_no_latches.zip 100-Round Square Flat10×10100 ShellsSquarePrint-in-Place Latches4-Box Sporting Clays Flatsquare_10rx10c_with_latches.zip 100-Round Square Flat (Sleek)10×10100 ShellsSquareLatchless Slide4-Box Sporting Clays Flatsquare_10rx10c_no_latches.zip Ammo Can Fitment Notes - Preset 12ga 10x4 m19a1 — USGI .30 Cal M19A1 Steel Can (40 Shells):- Standard 12ga boxes won't fit into the narrow opening of military .30 cal steel cans (internal dimensions roughly 254 × 89 × 165 mm). - This staggered 4-row by 10-column hex pack measures 246.3 × 87.6 × 67.6 mm, allowing it to slide cleanly through the top gasket opening. Two boxes stack two layers deep for an airtight 80-round transport case.

- Preset 12ga 9x7 hf30 — Harbor Freight .30 Cal Plastic Can (#63135) (63 Shells):- Harbor Freight's plastic field cans are inexpensive and everywhere, but their interior draft angle wastes space with boxy containers. - This 7-row by 9-column hex pack measures 223.2 × 147.7 × 67.6 mm, custom-profiled to drop right into the can floor and pack over two and a half full boxes of ammo (63 shells) in a single grab-and-go unit.

Component Breakdown (What to Print) Inside each configuration package, you'll find matching modular components: - box_no_backing: Solid heavy-duty box body with rim counterbores and interlocking perimeter channels. Print this if you're doing a standard single-material print. - box_with_backing: Box body with an internal cavity pocket for enclosed multi-material contrast plaques. - lid_pip: Print-in-Place lid featuring captive sliding dovetail latches and anti-lift corner interlocks. When printed cleanly, a firm thumb press breaks the sliders free to lock into their detents. - lid_no_backing: Latchless sliding lid that clicks shut using the built-in forward and rear detent nubs. - lid_with_backing: Latchless sliding lid with an internal void for the contrast plaque. - latches_plated & latches_multimaterial: Standalone latch sliders. If your machine struggles with Print-in-Place tolerances, print the latchless lid and slide these in separately. - stacking_lip: Modular snap-in / glue-in rim tongue that mounts along the perimeter channels so stacked boxes lock together during transport. - lapping_cartridge: A 12 Gauge dummy shell with a 1/4" hex shank and sandpaper kerf slots. Chuck it in a drill with a strip of 400-grit sandpaper and run it in each chamber for a couple seconds for silky-smooth shell extraction.

⚠️ Important Clarification on Backing Plaques (*_backing & *_labels) The backing plaques (box_backing and lid_backing) are not snap-in inserts or exterior covers. They are designed to be fully enclosed inside the printed shell material during printing to provide a contrasting, opaque backdrop behind debossed text when the outer shell is printed in transparent or translucent filament. A multi-material setup (Bambu AMS, Prusa MMU, etc.) is required to use the backing plaque parts. For single-material prints, stick with box_no_backing and lid_no_backing (or lid_pip). Slicer Notes & Print Tips - Outer Brim:- Shotshell boxes have a broad footprint. I strongly recommend enabling an Outer Brim on both the box body and lid to keep the corners from curling up off the build plate under cooling stress.

- Support Settings for Print-in-Place Lids (lid_pip):- DO NOT use automatic supports. If automatic tree or grid supports get inside the dovetail travel channel, you will permanently weld the latch sliders shut. - Add manual Support Enforcers only under the bottom overhang edge of the sliding latch piece. - Set support placement to "On Build Plate Only".

- Layer Heights & Infill:- 0.20mm layer height with 0.20mm first layer. - 3–4 walls / perimeters with 15–20% infill (Gyroid or Grid).