Also be advised, that at least post 1920-=after the Curtis forearm latch design was dropped, and all extractor guns above Field grade had the roller latch design- there is a difference between the J-looped shaped spring for the ejector guns, and those with extractors- I have a good supply of std J-springs, and they are all made after market, as are the top lever V-springs, slightly over length, for a final file to fit--Also, for the amateur TIG welders herein- aluminum will transfer heat away from the high carbon spring steels, but it can also contaminate the HAZ- I prefer to use copper chill plates- to each his own..
