I don't know about stagnation as much as it being a mature industry (technology). Face it, there is just very little room for real improvements by the end of 1880-1900. You had reliable single and double triggers, reliable extractors and ejectors, reliable barrels in both Damascus and steel, reliable openers on the top side and underneath and reliable locking lug systems in several different locations. It's all been invented and perfected. Those which did not work well were bypassed and those which remained were perfected further by tinkering.
