There are some that have been found that do indeed have human teeth marks on them. However majority of these are usually found in various camp site areas. Also not uncommon to find other carved ones nearby. Moreso the implied evidence of bored soldiers than anything of purpose. The so called Medical Pain bullet is generally a myth.
Majority of those found with what appears to be teeth marks... Are usually contributed to hogs, as well as squirrels, mice and other rotents... that find the soft lead of interest to chew on...
Frederick