I was wondering if there is a possible correlation between how well a carbine feeds (functions) and how new of a condition, or old and worn it is.

My original Inland is 95% to 98% finish and an ME of less than 1 (probably about "0").

My Standard Products mix-master's barreled receiver (and most other parts, too) is about 90%+ original finish, and an ME of between 1 and 2.

Both appear to have been shot very little, compared to many of the carbines I have had. Both function flawlessly with GI 30 rounders, no matter what ammo I use.

Granted, I replaced recoil springs in both prior to shooting, as a matter of course, and ejector and extractor springs in the mix-master. I still wonder, however, if old, much more used carbines are more prone to malfunction than lesser used ones.

While this is no way scientific, I wonder what experiences others have had
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