Which type of firearm is primarily used by boardings and law enforcement personnel in the Coast Guard?

The M870 shotgun is primarily used by boardings and law enforcement personnel in the Coast Guard due to its versatility and effectiveness in a range of scenarios. This shotgun is particularly suited for operations where close-quarter engagements are expected, such as ship boardings, where the ability to manage various threat levels is crucial.

The M870 is renowned for its reliability and ease of use, making it an ideal choice for personnel who need to respond quickly and efficiently in high-stress situations. Its capacity to use various types of ammunition, including buckshot and slugs, provides flexibility to adapt to different operational needs, which is critical in law enforcement contexts.

In contrast, while firearms like the M16 rifle or Glock pistol may be used for different operational roles within the Coast Guard, they do not offer the same level of close-range effectiveness and adaptability that the M870 shotgun does in boarding scenarios. The MP5 submachine gun, while also effective in particular situations, is not the primary choice for the Coast Guard's boarding teams, which favor the shotgun for its unique advantages in that operational context.