That will do the job beautifully. There is no "right" form for the cap; whatever you like is right for you and you'll only learn that by using different ones. I like the full dome as you show here, but others prefer something less pronounced and still others don't dome the caps at all, preferring the accuracy of strike provided (demanded!) by using only the edge, though if you like the weight forward it's difficult to get much lead in one that isn't domed. Now all you need to do is convince your friend to make up dies in a couple more sizes.