Believe it or not Poly Chokes work, ugly yes but the work. I have one from 1932 in 16 ga. that had it's Poly installed in St. Louis and cased in a wood and leather case marked Browning. Now it has a short chamber 2 9/16s", but plenty of ammo available for it. Browning never installed any add on chokes in Belgium, but if you ordered one it was installed at its St. Louis facility. Have a 3 SHOT Model made in 36 with a solid rib barrel that I have duck hunted with useing bismuth loads, it is choked full. Last but not least I have a Sweet 16 from 62, round knob, 28" VR mod. barrel. Shot a few pheasants with it, but really didn't like the wayh it handled. Then I found a 26" IC barrel with the matte stipling down the barrel. Now the gun became a more lively handling shotgun, really like it. And yes one may use stell shot in the barrels made in Japan. I just lucked years back and bought both bismuth and Kent Matrix for 12 and 16s on sale and close outs. Japanese made barrels cost almost more than any A5 I bought.