The NRA gets 1% of its funding from gun manufacturers and about 2% from gun dealers. The other 97% comes directly from THE PEOPLE. The NRA more directly represents the interests of individual citizens of the US than any other privately funded organization in the USA. Also, they really are not pushing a gun industry agenda, they are pushing a gun owners agenda.
Also, the NRA spends less than 5% of its budget on lobbying. Most of its money not spent on administrative costs and advertising goes to positive activities like education, training, competitions, and various charitable activities and events.
That's untrue, less than half the revenue comes from the people in the form of fees And membership. The bulk of their income is from advertising, mostly from the gun industry.