First hit on Google for "hunter crit cap"
http://www.warcrafthuntersunion.com/...rit-cap-guide/
Warcraft Hunters' Union is an amazing resource for hunter info.
If you're too lazy for that, the short answer is 104.8% (assuming you're hit capped, which you should be.)
75% is closer to accurate for melee since all npcs of equal or higher level have a chance to trigger glancing blows, which can't be pushed off the hit table by hit or expertise.