Could it be 'Shooting For Boys' by Archie Frederick Collins, published pre-1923?
If it was, it's been reprinted. (Paperback printed on demand in the USA)
Check Amazon or Abebooks for this ISBN.
ISBN:9781141715305
Thanks for the reply. I will find out if this has the poem inside. My only concern is the book I "remember" was British rather than American
I may of course, be wrong.