I'd say go with the 16" the 20" wont give as good as a performace as the 16" for hunting ranges, I'm assuming it wont be any farther that 200 yards? the 20 will just be an extra 2 inches for things to get snagged on in the woods and stuff
"It's not how big your stick is, it's how hard you swing it."
"When a man lies, he murders some part of the world.
These are the pale deaths which men miscall their lives.
All this I cannot bear to witness any longer.
Cannot the Kingdom of Salvation take me home?"