I shoot pretty boring stuff, 7X57 150's, 30-06 180's, 8X57 195's, .350RM 225's and they all pretty much use the 209 (like the primer) rule. 2" high at 100 = 0 at 200 = 9 low at 300. Beyond that it's time for this guy to do a little more hunting. The gap in the duplex is instant and works fine for ranging.
YMMV....

We eat organic in our house, we just have to shoot and gut it first.....