Yesterday afternoon I had a chance to play with the OAL some with the 140 AB/IMR 7828 ssc load I had some very good preliminary results with.
The first target is the first group from 4/28/14 with these exact same components and the first OAL I chanced to try. That is my starting point.
The second target (string 3) is with an OAL of 3.360" (bullet jump of about .050"). I measure the group at .65" center to center.
The third target (string 4) is with an OAL of 3.355 ". It shows a horizontal dispersion.
The fourth target (string 5) is with an OAL of 3.350". The same as my starting point with I suspected could be improved. Note the bi-modal horizontal dispersion.
The fifth target (string 6) is with an OAL of 3.340". Note the vertical dispersion.
The sixth target (string 7) is a repeat of the second target with an OAL of 3.360" Note that shots 1 & 2 are exactly in the middle of the group in the second target (string 3). That would make a seven shot group of .65". If these two shots were on the same target, it would have shown one ragged hole.
I don't know why shot 3 of string 7 is out of group. It would have been the eight shot in the above mentioned group and would have ruined the group. But since I had seven in row that were good I am willing to ignore it. It was the end of a long shooting session and I was probably tired.
I tried to adjust the scope with the last two shots which are on another target.
In reviewing these targets, I wish I had shot a string with an OAL of 3.330" My hunch is that it might have been pretty good. Maybe I will try that in my next session although I don't know if I can improve upon the group with the OAL of 3.360". Maybe I should also try 3.365" before I call the project complete........
The average velocity of all 20 shots was 2969 fps.
The first target is the first group from 4/28/14 with these exact same components and the first OAL I chanced to try. That is my starting point.
The second target (string 3) is with an OAL of 3.360" (bullet jump of about .050"). I measure the group at .65" center to center.
The third target (string 4) is with an OAL of 3.355 ". It shows a horizontal dispersion.
The fourth target (string 5) is with an OAL of 3.350". The same as my starting point with I suspected could be improved. Note the bi-modal horizontal dispersion.
The fifth target (string 6) is with an OAL of 3.340". Note the vertical dispersion.
The sixth target (string 7) is a repeat of the second target with an OAL of 3.360" Note that shots 1 & 2 are exactly in the middle of the group in the second target (string 3). That would make a seven shot group of .65". If these two shots were on the same target, it would have shown one ragged hole.
I don't know why shot 3 of string 7 is out of group. It would have been the eight shot in the above mentioned group and would have ruined the group. But since I had seven in row that were good I am willing to ignore it. It was the end of a long shooting session and I was probably tired.
I tried to adjust the scope with the last two shots which are on another target.
In reviewing these targets, I wish I had shot a string with an OAL of 3.330" My hunch is that it might have been pretty good. Maybe I will try that in my next session although I don't know if I can improve upon the group with the OAL of 3.360". Maybe I should also try 3.365" before I call the project complete........
The average velocity of all 20 shots was 2969 fps.
