You've already done more than 90% of the shooters out there by actually shooting at 200. If your calculations are based on the B.C. of the actual bulket you're using, you've done about all you can do short of shooting at 300. It would be better if you knew the actual velocity in your gun of course.
I'm hoping you also have enough sense to refrain from taking a 300 yard poke at an unwounded animal with your rig. Lots of folks that wouldn't dream of such a shot with a .30/30 or .44 mag rifle think it's perfectly okay to try it with a ML. I've got a nice accurate, scoped inline, but wouldn't try beyond 150 myself, and then only under the best conditions.
