I was looking through our reference library yesterday, and realized that we hadn't mentioned at Hatcher's Notebook before - which is a glaring oversight. Julian S. Hatcher (Captain Hatcher during WWI, and Major General Hatcher by WWII) was a presence in the US Ordnance Department for nearly 30 years, and was actually interested in firearms technology enough to record much of what was going on. He was involved in the US procurement of light machine guns, and development of early semiauto service rifles. In addition to all this, he had a curious mind and engaged in a number of interesting firearms experiments, the results of which are recorded in Hatcher's Notebook.

Hatcher's Notebook is an indispensable reference for anyone interested in early 20th century firearms development, and I really can't recommend is highly enough. Both hardback and paperback editions are still in print, and easily available, so pick up your copy today:

https://www.amazon.com/gp/product/0811703509/ref=as_li_ss_tl?ie=UTF8&tag=forgoweapo-20&linkCode=as2&camp=1789&creative=390957&creativeASIN=0811703509