Around October 2010, I bought my first NF, for kicks and due to the fact it was cheap. The spring and plunger rod looked like this (not my pic)
Fast forward to May 2011, I buy another one with a view to clip mod it.. and I get this
Ignore the black spring. That is a buzz bee spring addition. Nowadays the NF stock springs seem to be weaker with less coils and the metal seems thinner. (Or I could be all wrong and I bought a real Barry Crocker).
If I remember correctly, the NF springs circa 2010 were said to be smaller from previous years. So this seems like another step down