Brass is cheap and easy to machine. Pretty easy formula that SWFA is using , thick tubes, brass turretts and built by people with pride of workmanship, its not rocket science. NF has some more exotic materials they use , Titanium leaf springs and at least on the SHV i own brass internals, not sure what they use on their high end stuff. I think that along with attention to detail when assembling the scopes makes that difference. They can find the Duds before they hit the streets with their QA process as well.
Maybe someone can get a Leupold scope and a SWFA scope and have them cut lengthwise down the middle with a water jet to see the differences.
