Just as we witness the Winchester changing hands and its effect on those who possess it, so too, we see the consequences- good and bad- resulting from McAdam's hunt and the people he meets while engaged upon it.
To sum up, 'Winchester '73' is a really good movie, with an engaging plot and characters who have depth and dimension. James Stewart shows in it that he can handle darker movies and roles as well as lighter fare, and his supporting cast is solid as well, some of them- like Duryea- elevating the level of every scene they're in. Definitely one to watch if you're a fan of Jimmy Stewart, westerns, or just good movies in general.