Despite the small number of 8 gauges in the country, they were still banned along with all other big-bore guns in the early part of the 20th century as a measure to protect dwindling flocks of ducks and geese. With the 8 gauge gone, the 10-gauge became the largest legal gauge for waterfowl hunting.

Navy SEALs use the Benelli M4 Super 90, Mossberg 590, and Remington 870 combat shotguns. The Benelli M4 Super 90, also known as the M1014 Joint Service Shotgun, is generally preferred. It was first delivered to the U.S. Marine Corps in 1999 after intense testing.

Shotguns have an effective range of about 35 m (38 yd) with buckshot, 45 m (49 yd) with birdshot, 100 m (110 yd) with slugs, and well over 150 m (160 yd) with saboted slugs in rifled barrels. Most shotgun cartridges are designed to be fired from a smoothbore barrel, as "shot" would be spread too wide by rifling.

The 18, 15, 11, 6, 3, and 2 gauge shells are the rarest of all; owners of these types of rare shotguns will usually have their ammunition custom loaded by a specialist in rare and custom bores.