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Re: Up/Downhill corrections
This post made me re-think and analyzed the only extreme angle shot I made on game. The distance is only 618 yards but the angle was at 22 degrees. I was hunting, using my 300 Win Mag Model 70 Laredo LRH. I carried a trajectory table for this rifle shooting the Hornady 180 grain BTSP with a B.C of .452 at 3000 fps, corrected for 3500 ft. elevation - 76 degrees F at 50% humidity. This trajectory table was generated by a ballistic program written by Walter Fenchu, in DOS format. I still have the floppy disc that the program was downloaded to. It's an excellent complete ballistic program. I still used it from time to time. Anyway, it was late in the afternoon at around 7:45PM. the light was fading fast when I spotted the deer; a young 3X2, that just wake-up and was busy playing with two does. I lazered him at 618 yards. At the back of my trajectory table, I have a corresponding angle cosine multiplier, in 5 degree increments, starting from 10,15,20 and so forth up to 45 degree angle. I got my calculator out, yes, I did used a calculator, can you believed that - and punched 618 X .93, the 22 degrees cosine equivalent, which gave me the corrected distance of 574.74 yards. Looking at the trajectory table, the 575 yards, show's 10.2 MOA. The deer was barely visible now from the fast approaching darkness. It probably took me only 2 to 3 minutes, from the time I spotted the deer and did my computation. Anyway the deer gave me all the time in the world. He was busy messing around with the does. I turned the Leupold dial to 10MOA and added one more click, aimed, and then fired. I cycled another round immediately and re-acquired the target just in case but it's not necessary. I could see from looking at the scope, the deer was walking kind of funny and then he just dropped - dead! I have to wait the following day to retrieved the deer since by then it was really dark. Upon inspection-the bullet entered exactly within a few inches of where I aimed. Now I re-inputed all of these data into the Exbal and got .25MOA difference. 10.25 MOA according to my chart against 10.50 MOA from the Exbal. Close enough.
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To achieve the maximum possible accuracy, all variables must be remove or at least minimize.
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