Mike:
The study of how ordnance was manufactured and distributed is something that has not recieved a lot of research. Canada, the United States and the United Kingdom produced a vast array of ordnance for all three services and each service had its own specific way of packaging and supplying the ammunition to the user. As far as packaging is concerned it appears from my study that both the U.S. and the U.K. each had their own methods of packaging and as far as the Canada is concerned, during WWII it tended towards the British system. As for .30 and .50 cal ammunition for the Canadian Army in NW Europe, documentation and photographs show that the ammunition was supplied in U.S. manufactured metal boxes. I believe the boxes were delivered in wire re-enforced plywood crates that look similar to the ones used today for SA ammunition.
Here is an M1 .30 cal Box.
The M2 .50 cal Box.
