Change File Encoding to utf-8 via vim in a script

This is the simplest way I know of to do this easily from the command line:

vim +"argdo se bomb | se fileencoding=utf-8 | w" $(find . -type f -name *.php)

Or better yet if the number of files is expected to be pretty large:

find . -type f -name *.php | xargs vim +"argdo se bomb | se fileencoding=utf-8 | w"