I suggest reading Tom Davis' series in SAR magazine on the West Hurley Thompsons. You can find most of the articles on line, its now free, but it only seems to work with the Fire Fox browser or Safari A few; the search feature will probably find more http://archive.smallarmsreview.com/display.article.cfm?idarticles=4049 http://archive.smallarmsreview.com/display.article.cfm?idarticles=224 http://archive.smallarmsreview.com/display.article.cfm?idarticles=527