I looked through the posts here and didn’t find the answer I’m seeking. Possibly one of you will be able to shed new light on the subject. When sorting brass brass by volume, what purpose does it serve, other than a means of grouping brass into consistent bunches? Does actual volume influence accuracy? I generally try to develop a powder load filling 90% of the case. Is there a direct correlation between case fill and eventual accuracy? Am I overthinking this? Thanks, everyone.
Case volume question.
- Thread starter Topwater
- Start date
Jager
Gold $$ Contributor
Yes, case volume - and case volume consistency - matters a great deal... as it directly influences chamber pressure... and that directly affects velocity.
Historically, many handloaders have sorted brass by weight, as a kind of crude analog to case volume and case volume consistency. Actual, true case volume is a much better thing to focus on... but isn't really practical for large runs, as determining actual case volume is a slow, somewhat tedious process. Many of us will test a small sample set for case volume, and use that for the entire lot of brass.
Charge weight percentage matters because it affects how the column of powder combusts... loose powder sloshing around in a case will have wildly varying combustion characteristics. Near-full charge capacities, by comparison, up to and including compressed charges, exhibit far more consistent ignition, because the powder column is static.
Overthinking this is what we all do. No worries.
Historically, many handloaders have sorted brass by weight, as a kind of crude analog to case volume and case volume consistency. Actual, true case volume is a much better thing to focus on... but isn't really practical for large runs, as determining actual case volume is a slow, somewhat tedious process. Many of us will test a small sample set for case volume, and use that for the entire lot of brass.
Charge weight percentage matters because it affects how the column of powder combusts... loose powder sloshing around in a case will have wildly varying combustion characteristics. Near-full charge capacities, by comparison, up to and including compressed charges, exhibit far more consistent ignition, because the powder column is static.
Overthinking this is what we all do. No worries.
I try to make every round the same. This is one step I will not skip. Does nothing if you are loading to hunt. It is up tp you how accurate your ammo is. Just my two cents. Tommy Mc
It's about reducing or eliminating significant variables. If you have large ES's in volume, you're very likely to see large ES's in MV's.
Yes. Think how changing seating depth changes the case volume and how that influences the size of groups as you try to find an accuracy node.
Case fill will effect consistency as ignition can vary depending on how the powder sits in the case. I find the closer I get to 100%, the more consistent my MV's (and I've read that many other shooters have found the same thing).
I’m a bench rest shooter, out to 600 yds., slowly working my way out to 1000. I started reloading in 1968 to make my own hunting ammunition. It was a strictly an economic decision. Five years ago I got into precision shooting. I had no idea how truly ignorant I was. Things that I had never even considered, now become extremely important. The deeper I sink into this “ black hole “ the more intrigued I become. I too try and create the very best, most consistent reloads possible. Today is another example of an “ a-hah moment “. Thank you, Jager. Your comment about ignition rate and loose powder sloshing around in the brass makes perfect sense to me now. It’s similar to the first time a buddy of mine showed me the influence of bullet seating depth on group size. Folks here continue to be a remarkable resource of information. Thanks, guys. Please keep helping those of us who strive for deeper understanding.
Sandstorm
Gold $$ Contributor
This is Mecca of Reloading...and every day you learn something that takes you closer to your goal.
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