If it is a 3" Magnum Model 1100, it was made before 1987, because they quit making those when the 11-87 came out. It will most likely not function with light loads. Other than that it is a fine gun, and with a 2-3/4" barrel will be very versatile. I have a 1966 edition, and it is my main waterfowling gun. I have owned over 40 shotguns, and shot most of the others, but I still prefer the 1100.
What could have happened... did.