Many have fiber optics, red-dot lasers, and night sights, as well as law enforcement versions that elevate the capacity from six to eight shells with an added six in a horizontal side saddle adjacent to the receiver. Vertical column magazines holding 12 rounds are available in the
Russian Saiga
versions, as well as a traditional tube-fed version.
There are also short-stock and short-barrel "cruiser" versions from Mossberg that incorporate slings for recoil control and door breachers that can be affixed to the muzzle. This type of flexibility gives the shotgun the ability to mimic the rifle, but never replace it in its entirety.
These features allow individual officers and agencies the ability to adopt a rifle-shotgun hybrid. As a general rule, shotguns are less expensive than rifles because they have fewer moving parts, giving those officers and agencies with budgetary constraints the ability to arm patrol officers with added firepower.
Although these modern shotgun features are much appreciated by the law enforcement community, they will never replace the rifle's ability to place a single bullet on target over an extended range with extreme precision or the carbine's ability for quick and multiple followup shots at a respectable range and with manageable recoil control.
One must never forget that tactical upgrades to the shotgun are designed for "general" accuracy and will never replace the rifle's fundamental role for exceptional precision and recoil management.