If you believe the math that GS Customs publishes about bullet length vs. twist, then you sort of have to pick a bullet length range / twist / shooting distance combination to have optimal results.
The way I interpret it (and this is my novice understanding) is that if you over twist a short bullet, it will stabilize the bullet nose to be facing the original barrel direction throughout the flight, rather than the nose following the arc of the flight. (so it looks like it is slightly facing up after the apogee).
Since the nose angle is not perfectly following the flight path, drag will increase compared to if the bullet attitude exactly matched the flight path. In theory, this also can lead to tumbling at the target vs. a straight entrance.
Longer bullets of course have the reverse effect but seem to destabilize much faster if there is not enough twist.
For 500 meters, it looks like this is not a big deal, but the next 500 meters are more interesting.
It is not clear to me if you can use the same twist for the combination of a 300 - 425 grain copper bullet at 1 000 meters or not.
