Читать книгу Reloading for Shotgunners онлайн

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By varying the thickness of the plastic base wad, a huge variety of load combinations is possible without mandating extreme measures in component adjustments. Instead of adjusting component height, ammunition manufacturers logically utilize various thickness base wads to facilitate many different load types. This allows them to get by with few part changes in the hull’s construction.

At the opposite end of the hull from the base is the crimp and no matter whether the hull is paper or plastic it needs to be positively crimped. One purpose of the crimp is to seal the end of the shell to prevent the shot from falling out and keep dirt from entering. The crimp holds everything in order inside the hull. It also keeps the powder and shot properly packed for that micro-second when the primer ignites the powder and pressure begins to build. The crimp is a patterned fold and it is essential for proper powder ignition and controlling the burn rate. Varying the depth of the crimp or otherwise changing a pre-established fold can quickly and surprisingly affect the pressure.