Range actually doesn't matter too much when using the RR method. As long as your torpedoes can reach the target they always have a very high chance to hit, simply because the method maximizes the probability of hitting the target by all possible ways. It doesn't hurt to get closer, though, that way you can iron out smaller bugs in your data/approach etc.
Oh and try the Easy-AOB mod, IIRC it will give you full control over the range wheel as well!
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