A general rule of thumb for me, I'll put 2 oz or 50 gram tin in a half pint jar after opening it.

Using pint jars, it depends what the bulk is that I'm putting in there. If it is a crumble cake such as Plum Pudding, I was able to 6.5 oz in a jar with some air still around the large cake sections and not breaking it up. Being it is already packed fairly tight less space taken weighs more. I didn't want to break up the cake. For some flakes I may only get 4 oz because I don't feel like breaking them up and distorting their original shapes. For all regular cut blends, I'll get about 6 oz in a jar lightly packing them in leaving about 3/4" of air space on the top of the tobacco.

All that being said, with bulk I try to get in multiples of 8 oz. I then use on pint jar for long(er) term and one half pint for right now smoking.