From all the videos I've seen crazy dudes shooting stuff I guess most projectiles would shatter when colliding with anything harder then brick. The combined trajectory would be similar as in the above video but the projectile would have fanned out ... let me see if I can find that video:
Arma just stops tracking the projectile if it hits Steel and has not enough energy to penetrate. So I guess that's "realistic" enough. By that logic they should disappear when hitting the surface angled too though.
As said, I don't think the projectiles would break if they hit wood or even brick.