According to https://en.wikipedia.org/wiki/National_Rifle_Association#Finances https://en.wikipedia.org/wiki/National_Rifle_Association#Fin... the NRA receives

According to https://en.wikipedia.org/wiki/National_Rifle_Association#Finances https://en.wikipedia.org/wiki/National_Rifle_Association#Fin... the NRA receives the majority of its funding from small donors. I don't know what you consider "unbelievable", but it seems like the lack of corporate support wouldn't stop an organization like the NRA.