Emergency Bullet Keychain 9mm

Why I Like It

Let me be clear: nobody actually needs this. That’s completely irrelevant, because everybody wants it. The Emergency Bullet Keychain is exactly what it sounds like — a 9mm cartridge form-factor container, sized to spec, that opens into a tiny capsule for storing emergency items. It’s the kind of print that earns its place on a keychain purely through conversation value, and then stays there because it turns out to be genuinely useful.

What fits inside? More than you’d expect from a 9mm-sized cavity. A rolled-up bill, a spare key for something, a tiny pill, a folded piece of paper with an emergency contact, a small USB drive if you trim the housing. The form factor is discreet in a very specific way — it reads as decorative to anyone who doesn’t know what they’re looking at, but opens quickly if you do. Consider it a micro-cache with aesthetic credibility.

Print quality matters here because the tolerances on the cap and body need to be right — too loose and it opens in your pocket, too tight and it won’t close. PETG at 50% infill, 4 walls. Print the cap and body separately and test-fit before your final print. The cap should click on with light pressure and require deliberate pull to remove. Metal-look filament (silver, gunmetal PETG) makes the final result look disturbingly authentic. Fun to print, fun to carry, fun to explain.

What Filament Should You Use?

Here’s a quick breakdown of the three most common filaments for EDC gear so you can pick the right one for your setup:

TL;DR: Use PETG for most EDC prints — easy to work with and tough enough. Use ASA if the piece will live outdoors or in direct sunlight. Use ABS if you need maximum rigidity and heat resistance and have an enclosure on your printer.