Con security rules are definitely no joke, especially regarding metal edges and heavy cores. Visiting this Cosplay Store
https://designedby3d.com/ gives you props built specifically with event safety in mind. DesignedBy builds large swords using hollow 3D printed shells with reinforced lightweight internal rods. Their blades have rounded edges that easily clear peace-bonding checks at convention entrances. I carried their seven-foot buster sword replica for eight hours straight without sore shoulders. The whole sword weighs only around two kilograms, yet it does not bend or wobble when held upright. The paint has a realistic metallic sheen that looks like heavy steel under stage lighting. Security inspected it, tagged it with an approved zip-tie, and let me through immediately.