B.166 I
Size: Length 19.8" Breadth 9.1" Depth 13"
Used for:
3 in M.L. Mortar HE
3 in M.L. Mortar Smoke
3 in M.L. Mortar Chemical
3 in M.L. Mortar Practice
Number Packed: 6
Gross weight: 88 lbs
Grenades No. 73
Number Packed: 10
Gross weight: 62 lbs
Grenade No. 77
Number Packed: 34
Gross weight: 41 lbs
Grenade No. 79
Number Packed: 24
Gross weight: 56 lbs
Portfires, common
Number Packed: 200
Gross weight: - lbs
Bombs, P.I.A.T., H.E.
Bombs, P.I.A.T., Inert, practice
B.166 II
(your red box)
Size: Length n/k Breadth n/k Depth n/k
Used for:
Grenades, No. 73
Number Packed: 10 + 1 tube of 10 detonators
Gross weight: 62lb approx
C.255
Size: Length 25.1" Breadth 16.4" Depth 10.8"
Used for:
5.5-in. B.L. gun Cartridges Charge 4
Number Packed: 6
Gross weight: 99.5 lbs
C.298 is not in my reference, could be a Canadian box that wasn't used in British service.