Originally Posted by
Troubledshooter
There are three main series of the Webley Mk.II Service Air Rifle, 1st.,2nd., & 3rd., of which there were only 1000 made of each of the first two series.
There were two calibres when it was first launched, .177 & .22, with a .25 calibre added in 1937.
There are variants of the third series, and some have described the last variants as a 4th. series, although I don't subscribe to this idea.
The history of the Webley Mk.II Service is described in detail in Chris Thrale's book, Webley Air Rifles 1925 - 2005, which is a must for any serious Webley Air Rifle collector.