I have three, two of them were from my grandfather, a well worn 20 ga and a mint 12. He used the 20 for decades, then decided to upgrade to a 12. He took the 12 out, took three shots and missed at a pheasant. He then walked back to the car, got out his trusty 20 and never used the 12 again. That's how I came to have a 70 year old gun that's had 3 shots through it.
The third is a Sportsman variation that's US marked. It was used to shoot skeet as part of aircraft gunnery training in WWII.
Be sure the friction rings are set up correctly for the load you are using and keep the magazine tube lightly oiled with conventional gun oil.
http://www.browning.com/customerserv...ail.asp?id=105