Over the years I've had hunting discussions with PETA Members, Antis, what evers and I find that sticking to facts works the best.
Avoid tossing out insults - it just reinforces their opinions that we are all aholes.
Beat them with kindness.
Most polls I've seen show @10% hunters, 10% strident antis and 80% ambivalent. Might be better to work on the ambivalents.