RE: Practical accuracy
Just like we say in archery, practice like you hunt. If you are going to be taking off hand shots, you best practice them, same way with longer distances. I would never try a 200 + yard shot on live game without knowing me and the rifle could pull it off.
I assume shooting at game sized targets with a rifle would be simular to archery as well. Shooting at a bag target is NOT the same thing as shooting a 3-D target. It really helps you to learn bullet placement at different angles and what not.
I also agree that lower power scopes are usually better. The higher the power the harder it is to hold the gun steady, or find your game in the scope. I Normally get a 3-9 power scope for my hunting rifles, but rarely turn them up that high unless I am shooting off from a bench. My rifled slug gun only has a 1.75-4X scope on it. It's plenty for what I use it for. And it will shoot around 1 inch or so at 100 yards from a rest and the right ammo.
My 17HMR has a 20X scope on it and you can see your heartbeat in the scope sometimes.
Lot's of people think you need to see the bullet holes to shoot accurately, I just don't think that is the case. I think that is one of the reasons why someone switching from open sights to a scope has trouble at first. They have a hard time holding the gun steady. You don't notice so much with open sights. I tried a 4X on a pistol once and had to take it back and get a 2X, it was just too hard to hold steady off hand for me.
Not to mention you can get a much better scope in a lower power for the same price. $200 will buy you a really nice low powered scope, where it won't get much in a higher power scope. If I had to pick between high power and quality optics, I would take quality optics everytime.
Just my opinions though.
Paul