RE: 3" groups @ 25 yds?
I have my backyard set up to try and simulate hunting as much as possible. I let the grass grow long, tree branches hang down etc. I have my target block 10 yards from a group of 4 large trees that are all 20 yards apart from each other. I make 5 shots each round, one shot for each black dot on my target (4 corners & in the center). I make each shot from a differant location, in a differant position, sometimes hidding behind a tree or leaning up against one, etc. I don't have any yardage marks in that area but shots would range from 10 yards to 45 yards. If I can hit each one of those black dots with each of my shots, I'm happy. The dots are about 2" around.
To me that is the way a hunter should practice, try get as many varables into it as you can, then master it!