I am looking for a cross-section picture of recoil mechanism for french "75", but not schematic!!
I looked at many books, but I canīt find any detailed picture or photo (I found only schematic pictures). Therefore, I think, that the secret of "75" still continues.
How sealing of piston of pneumatic recuperator have been using? I found only information about piston-head, which sealed with german-silver rings.