The NRA is pro-hunting instead of being pro-second-amendment. Sometimes the two interests intersect, but not always.
The loss of the right to bare arms is perceived as an end-game. Once disarmed, there's no going back.
While the last decade or so has been good for supporter of gun rights, the entire 20th century was not. A lot of what gun rights activists are trying to do now is gain back some of the rights they lost in the 20th century.
As a side note, I think it is interesting is that 3D printer and other consumer-level CAD technology may be for the Second Amendment what the internet was for the First: a way to bypass government regulations altogether.
Please do not mistake my post for an endorsement of pro- or anti-gun viewpoints, I just want to clarify that the NRA isn't actually all that great for gun rights, and gun rights activists haven't been all that successful until recently.
The ACLU pretty regularly takes 4th and 5th Amendment cases.