Has the ACLU's stance on the right to bear arms has been inconsistent, as in, changed quite a bit over time? Or they just haven't had much of a stance to speak of? Honest question.
In 1991, they believed it was an individual right. Now they believe it's a collective right. I don't know of any major cases the ACLU brought on behalf of gun owners (but probably wouldn't know if they had).
I can't speak to that - but they also haven't felt as much of a need to devote resources to it as they feel, accurately, I believe, that the NRA has enough resources and a loud enough voice on that topic.
https://reason.com/2019/04/12/the-aclu-defends-the-rights-of... has some discussion of this.