RE: Bear size
For a close gussetamation on a black bears weight,Measure cross wise of the front pad print,,a 4 1/2 inch pad is usually a good size animal 300+ pounds.If you get a 5 inch+ pad your looking at a animal up in the 4-500 pound range.
It definnatly sounds like a nice size animal you have raiding the bird feeder.
Can you bait bear in your area ,if so I would get a bait station started sounds like he would hit it easy enough.
The average black bear harvested is 187 pounds,Anything in the 300+ range is a trophy animal.
I wish you luck in your persuite of your bear.