I'm not talking here about the best (from a military perspective), but the most technologically advanced from an engineering perspective. I would say that, during the First World War, the laurels go to the P 14/M 17. This rifle is properly production engineered (for the period) in a way that neither the SMLE or Gew98 were. It represents the peak of manufacturing and ergonomics that can be attained in starting from a G 98 basis, and is clearly well thought through (the dogleg in the bolt handle and the position of the safety catch, for instance). It certainly had the best sights on the battlefield, and is in my humble opinion a much better rifle from most perspectives than the M 1903 Springfields that it served alongside. For the Second World War though, the crown really has to go to the dastardly French for the MAS 36. Since this was basically a completely new rifle, they really could start from the ground up. From a production perspective, it really does have the minimum number of machining operations required to make the receiver, and the two-part stock helps production of that as well. From an ergonomic perspective it has everything that a rifle intended for a conscript army needs, and the only odd choice is why they cranked the bolt handle forward, since its positioning would have been ergonomically perfect had they just bent it straight down. Rear locking of course shortens the bolt throw and provides a good amount of receiver metal there for mounting a receiver sight. Perhaps the only other improvement would have been cooking on closing... Thoughts?