I’ll give my 2 cents as well.
Modern or current A5 is an inertia driven gun. Aluminum receiver. Wood stocked versions are pretty nice. The tupperware stocked ones are nice and good guns if you don’t care much about looks or you want something you can bang around with impunity in the duck blind. But they are good guns. This year, I hunted with a guy with one of the bronze sweet 16s. Very reliable gun. I bought a wood stocked version of the sweet sixteen.
Belgian Auto-5s were made with some of the best steel you could buy at the time. Hence JMB insisting “special steel” be stamped on the barrel. This is one reason they balance well. Because the steel was so good, it could be made thinner and lighter. They have great engraving and are rust blued giving them a really nice satin grey-blue finish. In my opinion, so of the prettiest on the market. Long recoil design led to the humpback with a great sight picture. Also many of the earlier versions had the matte rib on the barrel over a solid or vent rib. These guns are well know for their balance and “swingability”.
Cost of production got too high to continue making the Auto 5 in Belgium. So Browning went looking for a new place. Japan was known for great engineers and Miroku was considered a great gunmaker. So, production moved to Japan in 1976, I believe. They had to be built to Browning’s specs, but the “special steel” wasn’t in the cards. Now here’s some of what I didn’t know until Goosemaster posted his preferred date previously. Now here’s some of what I didn’t know until Goosemaster posted his preferred date previously and I started doing some reading. Japan Auto 5s were hot blued, hence the much darker and shinier bluing on those guns. Since the special steel wasn’t used, the barrels are thicker material and slightly heavier and some say less balanced. Internally, they are the same (as far as I know). I do know you can interchange the barrels and hear of people using an older auto 5 with a newer barrel with screw in chokes. engraving is the same, but not the same quality.
My son’s 1954-1955 Light Twelve is a beautiful gun. Engraving is sharp and the rust bluing is just perfect. My 1969 gun, while make in Belgium is hot blued and the engraving is not as sharp. But because mine is Belgian made, I feel like it balances just as nicely as his. I don’t have a Japan Auto 5, yet, to compare the balance to.
All that said, I’d like to hear his opinions on them as well.