jack boots is there a difference depending on country

[rwbowri]

today, I visited a army navy store that in another state, went there as it's 2 times the size of most military stores
found 3 pairs of jack boots, I was outside myself seeing them on the shelf.
they were labeled size 275, they looked almost the size of my shoes. I tried them on and couldn't get my foot in,
my toes just barely touching the insole of the boot very tight

I asked the clerk in the store and she looked about the boot and she said it was Korean and size 9.5 US

never wore jack boots but plenty of work boots that I lace up for work that go half way my calf.

Are the German and Russian jack books made the same tightness as this Korean?

I went on a Korean shoe sizing website sight and found out that Koreans have small feel, the average male is only around size 8 us
and only size chart up to 10.5 on their charts.