NRA publishes enemies list.

[JDPriestly]

44. Methodists alone number about 7.7 million in the US.

In the United States, it ranks as the largest mainline denomination, the second largest Protestant church after the Southern Baptist Convention, and the third largest Christian denomination. As of 2009, worldwide membership was about 12 million: 7.7 million in the United States and Canada,[6] and 4.4 million in Africa, Asia and Europe.

http://en.wikipedia.org/wiki/United_Methodist_Church

Some Methodists may belong to the NRA, but probably not one-half of them.

Plus Unitarians are a little over maybe a million.

http://en.wikipedia.org/wiki/Unitarian_Universalism#Number_of_members

On edit, almost two million Episcopalians also on the list.

http://en.wikipedia.org/wiki/Episcopal_Church_%28United_States%29

Non-members way, way outnumber members of the NRA.