I've been experimenting with different substitutes for heavy cream in making ice cream in order to get the "normal" ice cream texture. I thought it had something to do with fat content or possibly whipping enough air into the emulsion before I start freezing it (I use a Cuisinart).
Lower fat content, as we have discussed several times already on this board, seems to result in frozen-solid ice cream once it gets transferred into the freezer, so instead of cream, I started using coconut milk, which has less fat than heavy cream, but higher fat than whole milk or soy milk. My last batch was coconut milk in place of cream, and soy milk in place of whole milk (which had the added benefit of being entirely dairy-free), which actually produced a pretty good creamy texture once the ice cream is on the spoon.
The problem I'm still having is that, even with a higher fat content and additional whipping, my ice cream is still "crumbly" in that it doesn't hold together like normal heavy-cream ice cream. While this is fine in a bowl, it means I can't really put it in a cone, or scoop it out in a big scoop at all. It's still a little hard (as in solid), but I haven't tried adding the alcohol/xanthan/pectin that others have suggested, so I don't know if that would make a difference.