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with full-power loads.This is not the situation with typical, full-power loads with case-filling propellant charges. In such loads, using more heavily deterred propellants, primary ignition requires significantly greater granule heating and is associated with a relatively longer delay (with regard to how far bullet moves during that delay); secondary ignition and subsequent progressive progression of burning rate is relatively so slow that once bullet begins to move, gases generated by any newly ignited granules will contribute much less energy to bullet acceleration.

Ignition in Sporting Cartridges
Sans serious testing, which this author and Smalley are heading toward, I am loath to suggest that any specific numbers suggested herein are necessarily anything more than an educated guess but I will offer such general suggestions. Please, keep in mind that I offer these only as a means of indicating degree.

In typical sporting cartridge loads, several lines of evidence support the contention that plume generated ignition cannot reach far beyond about ž-inch forward of case web and that plume penetration depth is often less, perhaps closer to ˝-inch. Perhaps equally important, minimum primer plume penetration is approximately ˝ inch. As discussed in previous sections, primer characteristics have a surprisingly small influence upon characteristic penetration depth (at least as applied to primers that are both readily available to handloaders and that are adequate for the