400 Nitro Express:
I understand what you mean, but I do not agree.
Another example, this one from Peterlongo's 1934 catalog:
"6,5x52R (25-35 Winch.)"
So by this date Peterlongo (actually Richard Mahrholdt) reversed the naming; as I see it, another proof that this was considered the same, or interchangable, cartridge at the time.
With kind regards,
Jani