What is the correct ascending order of shotgun shell sizes?

The correct ascending order of shotgun shell sizes based on gauge is 0.410, 20, 12, and 10.

Shotgun gauges represent the number of lead balls of a specific diameter that make up a pound. A smaller gauge number indicates a larger shell size, which means that 10-gauge shells are larger than 12-gauge shells, and 12-gauge shells are larger than 20-gauge shells. The .410 is technically not a gauge (it's measured in inches), but it is used in comparison with gauges.

Thus, when arranged from smallest to largest, the order begins with the .410, followed by the 20-gauge, then the 12-gauge, and finally the 10-gauge as the largest size. This logical framework aligns with the specific sizing of shotgun shells, confirming the accuracy of the provided sequence.