January 5th, 2009

RELOADING TIP–Use Shell-Holder to Monitor Case Expansion

cartridge shell holderDuring load development, it’s important to check cases for signs of over-pressure. While you need to pay attention of a variety of factors, such as primer flattening and stiffer bolt lift, one sure sign of over-pressure is excessive case swelling at the web. A quick and easy way to monitor this is to bring a shell-holder (for your rim size) with you to the range. If a fired case won’t slide into the shell-holder easily, the diameter of the extractor groove has grown excessively and you know your load is much too hot… you’re way over-pressure.

Take note — if you get to the point that your case is hard to slide into a case-holder, your load is way hotter than it should be. So consider this an “extreme” measuring method. You should watch for other signs of pressure as well. As a rough rule of thumb, if we had a case that would not fit easily into the shell-holder, we would reduce the charge by at least 3/4 grain in a small case and 1.5 grains in a magnum case (and you may need to back-off the load further).

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