Bill, the 1187 Sporting Clays is very similar to the current 1100 Sporting 12. They are both chambered for 2 3/4" shells only.
A few years ago, Remington went through several gyrations with the 1187. Remington considered, or perhaps DID, drop the 1100 from production of a few years, but it seemed that many people wanted a gun with the numbers 1100 on it instead of 1187, even though they were essentially the same thing (in 2 3/4"). So Remington brought the 1100 back and dropped the 1187 Sporting Clays. Now, if you want a new Remington auto that shoots only 2 3/4" shells, it is called the 1100. If I were you, I would consider the 1187 Sporting Clays as a used 1100. If the price is right and it's what you are looking for, I wouldn't be afraid to buy it.