In 1976 Browning standardized its serial number identification which it followed until 1998. This would be an Auto-5 Magnum 12 ga.,manufactured in 1976 with the serial number 01001.

When did the Browning A5 come out?

Designed by John Browning in 1898 and patented in 1900, it was produced continually for almost 100 years by several makers with production ending in 1998. It features a distinctive high rear end, earning it the nickname Humpback.