Originally Posted By grendelbane:
Supposedly, some one in Finland actually did this trick in the early 20th century.
Don't try it at home. If you do, use it quickly, as the mercury will amalgamate with the lead.
Myself, I always wanted to see what a gold bullet would actually do. Probably won't ever get to, though.
It would make a hole. A very expensive hole. Given that it's more dense, a projectile of a given size would weigh more and hence penetrate deeper.