Let's apply a simple cost/benefit analysis to trying to move a long time lib/dem/anti to a more understanding position on guns.
1. The person is/has been a hard core anti.
2. There is a tiny possibility of getting them to be less anti, maybe even pro. They may continue to say they are Dem and have other Lib positions, but there is a small possibility of less resistance, even support, of less gun oppression.
3. Your actual cost in engaging them, NOTHING.
4. Worst case, nothing changes.
5. Best case, one less in opposition, maybe even a supporter.
Conclusion, with a cost of nothing, and a potential benefit of a gun rights supporter it's clear which is the better choice.
"It would not be perfect. Perfect is the enemy of the good, because, those who insist on perfect prevent the good from ever happening."
I grew up in a hard core Lib/Dem family, in a town that I call Libral Central. When I was a kid it was the people at the local F&G that convinced my Mother (divorced parents) to let me take up target shooting. The example they set and their open and fair attitude is what let me escape the cult. That and the game dinners were awesome. As an adult I've caused many Liberals to question their long time beliefs, who knows, some may someday see the light. The fight is a marathon, not a sprint.