ohiochuck,
On cases as small as 22 Hornet, it is difficult to get to the front of the rim, which is the "school" position to thin it from. With modern solid head case, it is my unlearned opinion that you can thin the rims from the rear. You can do one, then section it to see if there is enough brass left. If the primer pocket has to be deepened (maybe, maybe not), Lyman makes a tool that can be used( primer pocket uniformer) by hand. An additional benefit from thinning from the rear is that it removes the old headstamp.