I had projectile vomiting with my first son (he's now a healthy 15 year old). It was very alarming, u didn't know when it would happen (but was fairly frequent) and i couldn't give him any more milk for an hour or two or it would recur.
It worried me, til I heard someone saying that it happened with them with their baby, and it seemed to happen when he'd had just a little bit too much milk., then everything would come back up. Exactly the same thing that i saw.
I have to say that my older son suffered no ill effects from this.