"Longarms" or "long-arms" generally refers to rifles and shotguns, as opposed to handguns.

It's an important distinction, as something on the order of 80-85% of gun violence in the US -- rape, murder, robbery, suicide, etc. -- are with handguns.

Attempts to ban handguns have met stiff resistance, though, e.g. Heller v DC: https://en.wikipedia.org/wiki/District_of_Columbia_v._Heller