I hang out with a number of folks online who are DECIDEDLY left leaning, and play the token libertarian of the group. Everybody has fun and generally gets along pretty well, and friendly sass happens all around.
I've had a few who were sort of interested take me up on my offer to be the resource for all things weapon related. Some of them are from places as distant as Scotland, interested and willing to learn about things.
Even helping out one of them who had problems with the only gun owner he knew being a racist uncle. As in "has a gun that he refers to as nigger-popper" levels of ACTUAL racist. He had made some very disparaging comments about gun owners as a whole, painting with a broad brush, and my bf and I called him on it and explained how it wasn't helping, even with regards to the minority of gun owners that fall into that category.
I've been helping him to find a personal pistol to buy, he's leaning towards a Hi Power at the moment if he can find one he can afford. Doesn't care for the plasticy bits, I told him to go to a range and try a bunch of stuff, but pointed him towards a few of the good all steel guns and he was quite appreciative.
This is how we win. Force them to see gun owners as actual people with legitimate reasons for their choice to own and even carry, and they might just start to consider it.