My best (and most expensive) purchase so far is a set of Chinn "The Machine Gun", with all four volumes and the declassification letter..! Cost me £200 last year at the Trafalgar meeting at Bisley, which I thought was a bargain!

For those of you who do not know this magnum opus, it was written by George Chinn for the US Bureau of Ordnance in 1951, and is THE book on machine guns and cannon. Many of the illustrations, which are superb, have been reproduced many times in later publications...

Copies are on the internet, but nothing smells like the original!