So, as part of my reloading tools, I use the Hornady OAL comparator set to check COAL at the lands with various projectiles, etc...; I'm sure that many of you do the same.
Anyhow, I have been reloading for one Ackley-ized chambering (338LM AI), and using the off-the-shelf 338LM modified case to determine my COAL at the lands. I reasoned that it is close enough, and have to date just been too lazy to send a fireformed case to Hornady for modification (having the ass end threaded so it can be installed on the tool). I now have a second Ackley-ized chambering (.223 AI) to load for, and after thinking about it, I have decided that the headspace of the modified case and whether or not it is Ackley-ized is immaterial given the use of the tool. The reasoning that I am using for this conclusion is that it is not the shoulder to ogive measurement that matters, but the base-to-ogive measurement, which will be consistent regardless of where the shoulder is (relative to either the base or the ogive) or the taper/shoulder angle of the case. For that matter, even the length of the neck of the modified case is immaterial*.
What sayeth the Hide? Am I thinking correctly, or have I been eating paint chips again?
*The only time I can see the length of the neck of the modified case being pertinent with this tool is when the projectile at the lands does not have adequate bearing surface in the neck of the case... so it is pushed back in the case until it does (have adequate bearing surface in the neck), which will determine the projectile's jump to the lands.
Anyhow, I have been reloading for one Ackley-ized chambering (338LM AI), and using the off-the-shelf 338LM modified case to determine my COAL at the lands. I reasoned that it is close enough, and have to date just been too lazy to send a fireformed case to Hornady for modification (having the ass end threaded so it can be installed on the tool). I now have a second Ackley-ized chambering (.223 AI) to load for, and after thinking about it, I have decided that the headspace of the modified case and whether or not it is Ackley-ized is immaterial given the use of the tool. The reasoning that I am using for this conclusion is that it is not the shoulder to ogive measurement that matters, but the base-to-ogive measurement, which will be consistent regardless of where the shoulder is (relative to either the base or the ogive) or the taper/shoulder angle of the case. For that matter, even the length of the neck of the modified case is immaterial*.
What sayeth the Hide? Am I thinking correctly, or have I been eating paint chips again?
*The only time I can see the length of the neck of the modified case being pertinent with this tool is when the projectile at the lands does not have adequate bearing surface in the neck of the case... so it is pushed back in the case until it does (have adequate bearing surface in the neck), which will determine the projectile's jump to the lands.
