I can't cite a source, but I've seen some reports on both sides.
Some say it's too much of a pain to be worthwhile, and the failure rate is very high.
Others say it works great.
There was at least one somewhat recent article (last year or so?) about doing such, in either Handloader or Successful Hunter magazine.
The author there used the two-mold method, where the nose is poured in its own mold. Then it is placed into the other mold, for the second alloy to be poured.
Photos looked good. Text of the article claimed it was the 8th wonder of the world.
I believe hogs were also used as ballistic test media.