The Halo 5 Magnum was built to complete our Master Chief costume as a sidearm. After exploring different fabrication approaches, we decided to build it using 3D printing. The link to the 3D model used for this project is available at the bottom of the page.
The project began with a raw 3D print that arrived in 7 parts. Once assembled, we used filler spray and Bondo spot putty to fill seams and surface imperfections. After several rounds of sanding, the surface was ready for detailing.
We 3D modeled a new threaded barrel attachment to better match the in-game reference and designed a flashlight holder that threads directly into the body of the prop. Lettering and numbering were applied using cut vinyl, and a textured grip was added with stone texture spray paint.
After completing the surface work, the master was molded using Mold Star 30 by Smooth On in a 2 part box mold. During this stage we discovered that Rustoleum clear coat inhibits platinum silicone cure, which required a section of the mold to be redone. After switching to Krylon Crystal Clear, the silicone cured correctly.
Each mold half cured for 24 hours before casting began. The initial casts were made using Smooth Cast 300 resin, chosen for its fast cure time. Once the resin parts were cleaned and sanded, they were painted using layered acrylics to achieve the gunmetal and black finish. Weathering was added using black shoe polish, acrylics, and spray paint to create a worn appearance.
About a year later, we rebuilt the mold as a more refined 2 part version, allowing us to cast flexible rubber replicas using Task urethane rubber from Smooth On. These versions were cast solid with a wooden core and internal armature. Armature wire was placed inside the trigger guard to reduce flex and prevent breakage. Vinyl paint was used as a primer, followed by airbrushed chrome paint to create the aluminum finish along the top of the prop.
Special thanks to our interns Kendra, Alexys, and Alyssa from Sheridan College’s Advanced Special Effects Makeup, Prosthetics, and Props program for their help with sanding, molding, and casting, and to Sarah Christopher from MAG for assisting with the updated mold and rubber cast process.
Below is a photo compilation showing the build progress.
