Another Browning A5 Serial Number Question

So I traded a Glock for the Browning 16 gauge and am have no luck figuring out when it was manufactured. Any help would be greatly appreciated. The serial number is A18151.

"American Browning" made by Remington circa 1940.

Thanks! What’s the “code” for that serial number?

Remington produced Auto-5's are actually Model 11's with a magazine cutoff and Browningesque engraving. The easiest way to identify them is the serial number appears on the side. These numbers are outside of the standard FN/Browning system. The 16 gauge guns had an "A" prefix, the 12 a "B" and the 20 a "C".