I personally prefer to run my scopes for F-TR shooting from 300 to 1000 yd at ~32 to 36X. If I set the mag any higher than about 36X, I often can only see a small part of the target number board and run a very high risk of cross-firing. Even at only 32X, I do not have any noticeable difficulty holding as fine as I need to. For example, with a good scope/reticle, it is not difficult hold center-X, or left/right edge of the X-ring. The X-ring is 0.5 MOA in diameter, so that translates to holding an increment of ~0.25 MOA with a 32X scope out to 1000 yd. Frankly, my eyes aren't that great, but I daresay I could probably hold even a little tighter than that if I had to, although whether I can reliably shoot that tight is a whole different story

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I would strongly suggest actually looking through some of the scopes you might consider purchasing, if at all possible. Most of the time people at the range are more than happy to let you take a peek through their scope. If you see someone at the range with a scope you might be interested in, tell them you're potentially interested in that exact same scope, ask them nicely, and they'll most likely be happy to let you look through it. If you have the opportunity to do this, see what your own eyes can resolve at a given distance on a specific mag setting. Tall grass, small branches/twigs, rocks, shotgun clays, or targets of known dimensions can all give you a pretty good idea whether a given optic and/or mag setting is sufficient for your eyes. You really don't have to go "overboard" with magnification, but there is one fact regarding scope magnification that is impossible to get around: you can't turn a scope that is already on the highest mag setting up any further. So make sure you get a scope with sufficient mag for your needs.
You didn't give a lot of detail on the type(s) of shooting you intend, other than the distance (500 yd). Obviously, magnification is an important consideration, but there are also other features such as the quality of the glass, tracking and turret adjustments, reticle offerings, etc., that are also very important. A few more details on the type(s) of shooting you intend to do might net you even better feedback.