I believe that Buffalo Bore sells loaded ammo. I use it and it is very good ammo. If you want to reload, the bullets come from Rim Rock bullets. They supply BB with theirs.
200gr Jacketed not pushed to fast or hardcast bullets. I believe Federal is loading a JSP that is built strong. Hope you never have to put your gun and load to work.
I use Underwood 200 grain cast in mine. Luckily I can't tell you how effective the are on a grizzly. Some glocks don't like to stabilize the 220 but at the range you would be using them at that likely would not matter.