Currently shooting a 300 RUM with 200 gr. AB's at 3,120 fps. Went out a couple of weeks ago to dial in my scope to get accurate drop table for this load. Using the Excel program provided by Dave King on this forum, I was able to publish a drop table that was very close to actual performance. I only had to correct a couple of clicks at 500 yds. However, in order to get an accurate drop chart that reflected the actual bullet path, I had to go back to the software and change the B.C. of the 200 gr AB from the published B.C. of .580 down to a B.C. of .520. /ubbthreads/images/graemlins/confused.gif Now the software prints a table that is dead on and reflects actual bullet flight out to 700 yds (farthest I could shoot that day). Has anybody run into this before with B.C.'s for the Accubond? I didn't expect it to be off by that much.