Late WW2 1945 H51 Ammunition Box

These ammo boxes came by the end of the war, "1944/1945" 

The H51 box was introduced right at the end of World War II for use in the Jungle, “Pamphlet No11, Small Arms Ammunition “ dated February 1945 has the following description:

“Jungle Packages 16. as the result of requirements of a “Jungle pack” for S.A.A., Boxes H.50 and H.51 (not listed in Tables 14 and 15) have been introduced and will probably eventually become universal standard packaging”

A post war pamphlet describes the H51 and H50 boxes:

“These packages were introduced during the late war in order to give full protection to ammunition carried into jungle and tropic zones. The steel outer box is designed mainly to provide protection during transport and storage and during free or parachute dropping from aircraft.”