is this a valid question to ask about the NRA?

I noticed that the NRA is a 501c4 organization. according to wikipedia, this type of non profit:

"A 501(c)(4) organization may directly or indirectly support or oppose a candidate for public office as long as such activities are not a substantial amount of its activities"

i suppose "substantial" is not clearly defined but I would think that if they are spending more than half of their money on candidates, that would clearly be substantial

we've all heard about the millions the NRA gives to candidates. according to this, they would have to be spending MORE than that on other programs that do NOT support candidates directly or indirectly.

is there any evidence that they spend as much as they do on candidates on other programs? that would be a lot of money.