My TB is riding a fine line between L and XL bell boots.
The L don't quite cover and rub his heels, but the XL come off really easily and I'm not totally comfortable galloping in them.
So... I need a pair of really big L or really small XL.
I think he's wearing the italian rubber XLs right now and they're a little smaller than whatever I originally had (swapped his with my DRAFT CROSS *sigh*) so the fit isn't as enormous, but they still don't stay on.
sounds like you're looking for pull-ons, not the velcro on/no-turn ones, correct? i have the same issue with my TB in the Italian rubber double thickness bottom ones - the larges are a wee bit too small (and evil to get on) and the XL are a wee bit big and flop around a lot and therefore tear faster.
Try some of the cheaper brands of the same type. I have 5 pairs of XL bell boots that don't fit either of the horses I bought them for. Both have big feet, though my TB's aren't so big that he should need an XXL! The ones I ordered were the Centaur Pull On Bell Boots from Smartpak. Prior to that order, I had always ordered the XLs from Beval and they fit great. So much for trying to save money!