ammo tray 3d model

Generate a high-quality, 3D printable STL model of a simple rectangular ammo holder tray for 6.5 Creedmoor cartridges. Overall dimensions: 150mm length, 220mm width, 50mm height. The tray is a solid rectangular block with an array of tapered holes arranged in a tight grid of 11 rows by 16 columns (total 176 holes), centered on the top face with at least 1mm material between holes and minimum 1mm walls around the edges for structural integrity. Each hole is designed to hold a cartridge bullet-down for stability: from the top surface down, first a cylindrical section with 12mm diameter and 14mm depth (for the cartridge body); then a conical taper section with 30-degree shoulder angle (tapering inward from 12mm to 7.5mm diameter); followed by a 7.5mm diameter cylindrical section extending to the full remaining depth (about 50mm total hole depth). Ensure the model is watertight, manifold, with clean topology, no overhangs over 45 degrees, minimum wall thickness 1mm, and optimized for FDM 3