Continuing with my 2 cents,-- I think there are a lot of things in the "necessary but not sufficient" category when trying to identify what makes a gun truly exceptional. One can round up all the usual suspects, from "correctness" to craftsmanship, and still not quite get it. After all the other dimensions of a gun are "right" in a more or less technical sense, it seems to me that, in the end, the gun has to be about itself, not its maker's ego. It has to possess a certain "autonomy". Meaning, all of its technical and aesthetic attributes are in the service of its reason for being as something that has to "work" while making sense to the eye and the mind. It's not trying to slay me with self-conscious virtuosity in the way it's designed and assembled, or seduce me with a heavy decorative overlay on all the surfaces. (Some current work that's patinated/distressed to within an inch of its life isn't necessarily any less sterile and devoid of "soul" than the work that looks like it was untouched by human hands.) And it's certainly not jumping out at me first and foremost as someone's "signature" piece.
One of the most compelling intangibles with 18th Century American guns, for me, is the evident humility of the makers that one can sense in many of them. Even the most stylistically exhuberant guns, the distinct minority, have qualities of restraint. Even anonymity. Whether it was because the maker was humbled by a sense of his place in the Great Chain of Being, or by the hardscrabble economics of an existence that kept him from going off the deep end into overwrought and time-consuming excess, the really exceptional guns have the feeling that their priorities, from functionality to aesthetics, have been kept straight. And that the maker was working within a sense of limits in terms of both practicalities and propriety.
The original work was taking place for reasons and within a world view that's largely vanished. The question of what makes a great rifle is arguably becoming more difficult, not easier, to answer as we continue to get farther away in the 21st Century from an understanding of the priorities that made people tick in the 18th.
