Yes there are a lot of people who fall into that category, the libertarian who believes in some help one. I certainly wouldn't be too far from that.

I once asked on a libertarian community what kind of volunteer work/charity work they did.

There were people who gave blood, or gave a little to charity. One person maybe mentioned volunteering as a tutor, but that was about it. I do know one woman who is very vocal about her libertarian path and she makes a point of making volunteer work a big part of her life. THAT I could deal with, if I saw a lot of the hard core libertarians at least volunteering to help the les fortunate. But I am not seeing that.