What size shell does a mossberg 500 take?

The Mossberg 500 shotgun typically takes 12-gauge shells, but it is also available in other gauges, such as 20-gauge and .410 bore. The shotgun can accommodate both standard-length shells (2.75 inches) and longer shells (3 inches) in the 12-gauge version. Always refer to the manufacturer's specifications for your specific model to ensure compatibility.