Zach,
If you get to a shoot or show with vendors, find a display of gloves and try them on regardless of the size marked on the glove or the package. I have found a lot of differences in diameter and length of finger stalls in packages marked the same size. This is one of the reasons I won’t order one from on line dealers. American Leathers makes great gloves, but they are the brand that has the most variation in size, at least when I try them on. Sometimes I take a medium, sometimes large. Their buffalo leather glove with the nylon insert between two layers of leather has the longest and biggest diameter of finger stalls of all their models—again, based only on my trying many on to get the ‘right’ fit.