Which of the following is not a type of round you would use in the M500?

The M500 shotgun is designed for a variety of ammunition types, including 00 Buckshot, rubber rounds, and slugs, which serve different operational purposes such as crowd control, breaching, and engaging in situations requiring lethal force.

00 Buckshot is a standard choice for engagements that require a higher volume of projectiles to increase hit probability against a moving target. Rubber rounds are non-lethal and often used for crowd control or training scenarios, allowing operators to subdue subjects without inflicting serious injury. Slugs provide a single solid projectile option for situations where accuracy at longer ranges is more critical, as they offer the ability to engage targets effectively at extended distances.

In contrast, incendiary rounds are not a typical or appropriate choice for use in a shotgun like the M500. These rounds are designed to produce fire upon impact and are generally not compatible with the intended use and operation of standard shotguns, which are more suited for less specialized ammunition types, particularly those meant for law enforcement and military applications. This highlights why incendiary rounds are not associated with the M500 as a usable type of ammunition.