Gentlemen,
Forget about developed tolerance, wind, whatever, and concentrate on individual encounters. LOOK at the study I refrenced and the unequivocal reality a charging Grizzly presents. Unless you've got a 50 cal Bearspray is without question your best option, period. However much you want to speculate the historical record and reason are what they are.
Just an FYI Grizzlies and Blackies are congreagting in the GYE in odd fashion. We have a sow, 2 cubs, AND a blcak bear boar on and off the compound here. Big boar Grizzly less than a mile away recently too. That poor Pine Cone crop is really starting to mainfest itself.