A 1/3rd Scale 120mm Armor Piercing, Fin Stabilized, Discarding Sabot - Tracer (APFSDS-T) round used by some NATO main battle tanks such as the M1 Abrams.
Print out 3x each of Sabot 1, Sabot 2 and Sabot 3. Requires some assembly (superglue), it helps to be an octopus... I used a piece of the penetrator to serve as a guide to ensure the sabot pieces lined up correctly while the glue dried. There is still a bigger gap between sabot petals than I would have liked, but it helped reduce some fitment issues.
A test print on a CR-10 came out satisfactorily, but it may require some light sanding and minor fitting. I tweaked the design very slightly after the test print to improve fitting, so if you encounter any issues let me know.
In the future I may add cavities in the sabot petals for magnets to help keep it together while it's not in the case. Enjoy!