I have a .30-.30 Marlin too. I bought it from a guy in 1978. He wanted to be a "hunter". He took it out of the box, (didn't even site it in), went out in the woods ONE time, didn't see a deer, never went out again. So i got it (with a scope) for $60!
I LOVE that rifle. I have taken quite a few deer with it. The farthest shot i made was a perfect heart shot at 130 yards.
With that kind of rifle, you'd have to hold about 2 feet over the deer's back to make a 200 yard shot.
I thought of getting a more powerful rifle, but i love the one i have cause it is light to carry, and doesn't have an overpowering recoil.
Besides, rarely do you get a shot at more then 150 yards where i hunt. Most are 130 yards and in.