This is an Improved model D that I recently picked up. These rifles were made from 1908 to 1914. Based upon the butt plate and tap plate markings, this particular rifle was probably made closer to 1914 than 1908. I haven't chronied it yet, but it shoots hard, so I'm confident it'll be around the 550 to 600 fps mark. According to The Book of the BSA Air Rifle by Milewski it is a Sporting model which is the name used when describing the number 2 bore (.22) rifles that are 45 3/4" in length. These later became the Standard model (in 1914 and continued post war production).