Just like anything else that has been on the market for a very long time, the luger pistol design was improved now and then. The last years the empfasis was on the steel composition. In the early years, they still had difficulty producing a coherent strong steel type, which led to differences in hardness and brittleness. An old article, about 1911, stated that barrel boring drills would sometimes wear out after doing only a few barrels, while others would last for many barrels. Also, local hardening techniques progressed over time and the quality of the spring steel improved.
Interestingly enough, Mauser, for example, did not use German steel in the early years (around the turn of the century - 1900), but Sheffield steel because of the better quality.
Anyway, it is expected that early guns can be damaged easier than the later ones. Something to consider with ammunition as well: The older the gun, the milder the load. A late 1930s, early 1940s Mauser will eat just about anything.
|