Many Western Boots /Cowboy Boots are manufactured around the world so allow for different sizing.
Uninted States ,Mexico,and Brazil are 1 size larger than your size boot for eg Us boots size 8D=7.5 australian
these Boots are in Us sizes D,DD,DDD,or E,EE.EEE.W depending on what is on offer.
Uk sizes are most same as Australian. (42)(43) METRIC SIZING SIZE 7.5 AND 8 or IMPERIAL NUMBERING
Italian sizes are 1/4 smaller than Australian (but dont worry )they stretch as made of leather and expand after wear. allow 1/2 size larger than you would normally wear.