FB,

I don't know anything about that particular spring but I can tell you that Wolff Springs has been around a long time here in PA and should know what they are about. I believe they are located in Spring City, PA.

I would not be surprised to learn that Brownells gets their springs from them.

"Americans have the right and advantage of being armed-unlike the citizens of other countries whose governments are afraid to trust the people with arms." James Madison