In the 10" twist guns we had a Perry, the tumbling bullets never would have made it 1000 yards. I know folks with 12" and 13" twist barrels have hit at 1000. but not always. The LRFS was actually the second time I've seen 168's tumble. The first was at a Gunsite Precision Rifle class. We had all purchased ahead some PMC match ammo offered as an option for the class to buy to avoid shipping ammo ahead and that was loaded with the 168. One of the targets was a 748-yard steel "popper" across a valley from us. The wind through the valley was an essentially constant 20 mph, and nobody could hit the popper, even with 12" twist guns. Bullet impact dust clearly showed them hooking left then right then diagonally and never repeating the previous POI. And the valley ridge we were firing from would have been at nearly 5,000 feet. So, enough wind, and the instability seems to appear starting right around the 700-yard point. My rifle and a number of the others had 24" barrels.
