darrindlh
Well-Known Member
No prob. thanks so much
Brian,
Yesterday I sighted in two loads with my 6.5x284 target rifle, one with 123gr SMKs and the other with 142gr SMKs. Elevation was 4170ft, 34 degrees F. I recorded muzzle velocity averages and noted that the cold barrel shot was 29fps slower than the average and the 2nd shot 12fps slower than average. Today I took it to a friends place who has gongs up to 1000yds. The elevation was only 1800ft so the atmospheric pressure read by my Kestral was quite different than from where I sighted in, as well as being warmer. I made the assumption that the 100yd zero would
be the same at both elevations. In the new conditions I had to resort to trial and error with the Moball computer to find a sight-in range that gave me the same
100yd point of impact as when I sighted in the previous day under different conditions.
The moment of truth was at hand. I decided to try it first at 1000yd. I input all of the conditions and used the G7 B.C. published in your book. For the first shot I dialed in the "cold barrel velocity" as being 29fps slower. To make a long story short I nailed the 1000yd gong, which is 26" in diameter, with the first shot, and the 2nd, and the 3rd, etc. I quit after 6 shots and no misses. This was with the 123gr SMK. I then went through the input process again with the 142gr SMK load, which during sight-in had produced an extreme spread of 5 and a SD of 2. I fired 3 rounds, all center hits, and then asked each of my spotters to try a shot. The resulting 5 shot group at 1000yd was perfectly centered and looked to be about a 5" group.
Several hours later We tested the rifle and your ballistics at rocks on a far hillside, having an uphill elevation of up to 12 degrees. We shot at 772yds, at 1\2 mile [880 yd], and at 999yd. In all cases the elevation dialed in with the numbers produced by the Moball computer were perfect, We did have a little more trouble on the wind axis. The last shots of the day were at 999yd where I fired 2 shots and each of my spotters fired one.. All shots hit the rock which appeared to be about 9 inches in diameter. In conclusion I cannot begin to tell you how pleased I am with the performance of Moball using all of the understanding and B.C.s provided by your book.