just find a country road and shoot when there isn't anyone coming along
I know, not really a good idea, but sometimes things like that seem like the easiest thing to do.
Try a couple things from inside the house (parallax and eye position): test the parallax on your scope, just point it out your window at home at something 200 yards away and move your eye up & down a little while looking through the scope. Test to see how far the x-hair moves on the object you pointed at at first (be sure no one will be spooked at a gun pointing out your window). It SHOULD move a little, if your scope's parallax is set at 100 yards! This could indicate that your eye position is causing the bullet to hit somewhere other than where you want it to.
Then, set up like you are going to shoot. Get the scope lined up at whatever (a small object, and about 200 yards away!). Then, without moving your eye, look around "inside" the scope to see if you eye is right in the middle of the scope. You will likely see a black ring around the outside of the scope. (this would also likely mean that your eye is too close to the scope, and you maybe should move the scope forward if you can) - be sure the black ring is even all the way around and up & down - if you move your eye slightly you will see what I mean (also move your eye closer/farther from the scope and the ring gets bigger/smaller).
Ideally, you really shouldn't see any ring (or very small) - this has to do with how close your eye is and the "eye relief" of the scope. And if you do see a ring, it should be a perfect circle all around the x-hair or you will be "off" when shooting.
If this isn't happening correctly, this could easily have something to do with your shooting (if your eye is set up too low in the scope, it will shoot low). OK, I'm not sure if your eye high or low will mean you shoot low/high, that is a guess, but it WILL affect the shot.
this is at least somethign you can check out without going to the range