How much bedding is usually required, with these higher quality, aftermarket stocks such as McMillan?
Do you mean how much actual bedding material is needed to bed a stock, or are you asking about how much "fitting" is required before you bed the action?
Unless the barrel channel doesn't fit and needs to be opened up, McM stocks generally don't require much fitting and as for the actual amount of bedding epoxy needed, a couple ounces.