Even using the heavier 55gn Bergers, it really falls apart quickly at 600yds when the wind is changing. Yesterday's results at 500 were some of the best I've seen so far and were partly due to excellent conditions with mild and steady wind.600 Yard Performance - - - My notes show I shot on a practice day at the 600 yard range using my one-in-12 Hart-barrelled "live varmint" 20 VT. I used F-Class rests and target. We took turns pulling and pasting targets in the pits and I don't have the target as the targets were reused. My notes say after 2 sighters "very few 9s - about a minute of angle." This is with my 39 grain Sierra hunting bullets. Oh, and I had chronographed the load and confirmed the scope's elevation calibration, but it took 2 3/4 minutes more elevation than the ballistic tables would have predicted.