Load Density / Case Fill %
How full the case is, as a percentage. Measure case capacity yourself with the water-weight calculator below.
How this works
Case capacity is most precisely measured in grains of water (see the Case Capacity calculator), but powder doesn't pack at the same density as water — the density factor adjusts for how a specific powder's granules actually fill the available space compared to a liquid that fills it completely.
Why load density is worth tracking
Very low load density (a small charge in a large case) can sometimes lead to inconsistent ignition and more shot-to-shot velocity variation, since the powder isn't well-positioned against the primer flash every time. This isn't a safety calculation on its own — always work from a published load manual for safe charge weights, and use load density as one more data point alongside pressure signs and chronograph consistency.
Frequently asked questions
Is a low load density dangerous?
Not inherently, but very low load density (a small charge in a large case) can sometimes lead to inconsistent ignition and more shot-to-shot velocity variation — it's a data point to watch, not a safety calculation on its own.
Where do I get my case capacity number?
Use the Case Capacity calculator, which measures your actual case volume from an empty-versus-water-filled weight — a real measurement is far more accurate than an assumed generic capacity.
What powder density factor should I use?
Start at 1.0 (same as water) if you don't have a better number — different powders pack somewhat differently, but 1.0 is a reasonable default absent more specific data for your exact powder.
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