On the bottom of the barrels you will see 2 numbers, eg 280 275. They would test fire the gun. This was the pellet count 280 with 275 in the target. The 1900 was made from 1900 to 1910. Approximately 99,000 were made. They were offered in the following grades:
K – Remington steel barrels
KE – Remington steel, auto ejectors
KD – 2 stripe Damascus barrels
KED – 2 strip Damascus, auto ejectors

There is a very good book which includes the 1900, REMINGTON DOUBLE SHOTGUNS by Charles Semmer.

Pete

http://www.damascus-barrels.com/Movie.html