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Full-Text Articles in Mining Engineering
The Effects Of Physical Flash Hole Deviations On Factory-Grade Rifle Ammunition, Nicolaas Martin Schrier
The Effects Of Physical Flash Hole Deviations On Factory-Grade Rifle Ammunition, Nicolaas Martin Schrier
Masters Theses
"The objective of this research is to determine the effect of dimensional and positional changes of the primer flash hole on the performance of factory-grade rifle ammunition. The studied variables were flash hole diameter, offset from center, and orientation of the offset in the primer pocket. Cartridge performance was quantified by measuring muzzle velocity, chamber pressure, and target grouping size (precision).
Five different flash hole diameters were tested for both the Remington .223 and Winchester .308 calibers: 1.4mm, 2.0mm (the Fiocchi standard), 2.4mm, 2.8mm, and 3.0mm. Each diameter was tested at three offsets: centered (no offset), 0.5mm from center, and …
The Effects Of Short Delay Times On Rock Fragmentation In Bench Blasts, Margaret Ruth Hettinger
The Effects Of Short Delay Times On Rock Fragmentation In Bench Blasts, Margaret Ruth Hettinger
Masters Theses
"Optimized rock fragmentation is essential for minimizing downstream costs to mining operations. Photographic fragmentation analysis, vibration monitoring, and high-speed video all provide measurements of blast effectiveness and supply data that allows operations to modify blasts to achieve downstream goals.
This study evaluates the effects of short hole-to-hole delay times on rock fragmentation. Photographic fragmentation analysis and various delay times were used on the same bench blast, the effects of timing on fragmentation were determined. This analysis provides a representative understanding of timing effects on fragmentation in the field, different from previous blast models which either negate the effects of timing …