Both of these shops are top shelf to deal with:

Track of the Wolf has .36 cal T/C Maxi's:
http://www.trackofthewolf.com/categories/tableList.aspx?catID=2&subID=25&styleID=65

The Possible Shop has .36 cal Buffalo Bullets (my choice for the price of $13.50/qty 50):
http://www.possibleshop.com/ball-bullet.htm

Tahquamenon