If you're within a reasonable distance from a good flyshop they're generally more than happy to let you try on various sizes for a good fit, and will happily assist in a rapid return if you buy or order a pair there.
Of course it's completely despicable to use a flyshop as a sizing opportunity and then purchase them online to save some coin.
Of course it's completely despicable to use a flyshop as a sizing opportunity and then purchase them online to save some coin.