I'm not completely sure how/why I did it but I put together some inconsistent copies of my 155 Scenar/IMR 4895 load. I went from a fairly solid 3/4moa to 2+.
I'm confident in my powder charges but where I've found problems is when I got my Hornady headspace and bullet comparator out. I have cases with 2 different headspace measurements, 1.620" and 1.625". Distance from base to ogive 2.185",2.197, 2.200", and 2.205. Fired brass measures 1.626 if it matters.
I "think" the original was at 1.620" on brass and 2.2" to ogive. I measured all of the 100 that I loaded and pulled 4 different combinations out.
1.620",2.200"=.58" shoulder to ogive
1.620",2.205"=.585"
1.625",2.185"=.56"
1.625",2.197"=.572"
Since I have two headspace measurements .005" apart and different base to ogive lengths the distance to the lands will be different with each combo because the 1.625 brass is going to seat .005 further off the lands than the 1.620 for the same base to ogive measurement right?
Basically that's why I subtracted the heaspace measurement from the ogive measurement because that should give me a consistent jump to the lands for each group right?
Am I making any sense? I really don't want to have to pull them all back down and start over.
I'm confident in my powder charges but where I've found problems is when I got my Hornady headspace and bullet comparator out. I have cases with 2 different headspace measurements, 1.620" and 1.625". Distance from base to ogive 2.185",2.197, 2.200", and 2.205. Fired brass measures 1.626 if it matters.
I "think" the original was at 1.620" on brass and 2.2" to ogive. I measured all of the 100 that I loaded and pulled 4 different combinations out.
1.620",2.200"=.58" shoulder to ogive
1.620",2.205"=.585"
1.625",2.185"=.56"
1.625",2.197"=.572"
Since I have two headspace measurements .005" apart and different base to ogive lengths the distance to the lands will be different with each combo because the 1.625 brass is going to seat .005 further off the lands than the 1.620 for the same base to ogive measurement right?
Basically that's why I subtracted the heaspace measurement from the ogive measurement because that should give me a consistent jump to the lands for each group right?
Am I making any sense? I really don't want to have to pull them all back down and start over.
