There are far too many exceptions to say older guns were better, and/or maybe not so good.
Many older guns required precise final hand-fitting. A part, for example, cast, forged, stamped, whatever, just may not fit in the area it's supposed to. That's where the true craftsman would apply a file, a stone, or buffing wheel to make the fit precise. And such a precise fitting throughout a firearm could make that firearm smooth. And such tight tolerances could also make a gun balky. Often we hear folks claiming any given gun requires breaking in. That's to cause tight mating of components to wear into themselves.
Modern guns however, cast, forged or stamped, are created with such great tolerances that any given part can be pulled out of a box, installed in a gun, and be expected to work without final fitting. That makes the gun more likely to operate under more adverse and/or different conditions.
There have also been countless metallurgical changes or improvements. Softer metals of the past would rely on surface hardening for longevity. And these softer metals may have been easier to polish. Newer metals may have a longer longevity, but polishing may be difficult. Smoothness is obtained by greater tolerances and lubrication.
So, yes, older guns were often made with far more care, precision, etc., but modern guns are very likely to always operate.
Older guns too, every surface may be mirror polished, allowing a bluing treatment to emulate looking into a mirror or pool of blue water. We can't afford that now. Finishes are created on a machine with billions of microscopic flaws that after bluing or otherwise coated, are touted as a matte finish.
Even a firearm as new as any given Ruger, first produced in 1949, has a far nicer finish and even nicer feel than more recent productions.
I have many older Ruger's, seemingly flawless. They live in a safe and come out usually/only for show and tell. But my newer Ruger's are used often. Both do their intended job as well as the other. The newer Ruger's are easily purchased and easily replaced. The museum pieces, once they're gone, they're gone.
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