Case Life

I recently met a new handloader, and the subject of case life came up. The simple question of how many times can you reload a given case has no simple answer. Factors that affect case life include: case design, case hardness, operating pressure and the size of the chamber the case is fired in vis-à-vis the size the case is squeezed to.

Last week I was processing some .38 Special cases in preparation for a mass loading. Many of the cases were acquired a long time ago, and a lot of them were pretty old then. As I ran them through the decapping die I noticed the handful of military surplus cases that remained a part of this cobbled-together lot. One had a headstamp of “WCC 58” (Winchester Cartridge Company 1958). Its mouth had the first vestige of a split, so I had to put it into the scrap bin. I have no idea as to the history of this 54-year-old case prior to it coming into my possession in 1974. However, I do know that in the 38 years I have had it that the case has been reloaded close to 100 times. My standard target load of 4.5 grains of, then Hercules, now Alliant, Unique behind a 148-grain cast wadcutter is very gentle. The .38 Special is a straight-walled case, so during resizing little metal is moved, therefore there is little metal fatigue. In fact, the only metal fatigue in this case was right at the mouth where it was crimped to hold the bullet. Military cases tend to be thicker than commercial cases. Winchester brass tends to be a bit softer than other brands, making it more malleable. All of these factors contribute to a longer case life.

On the other hand, some .300 RUM cases I have loaded needed to be scrapped after just three reloadings. Big Green’s big .30 is a large, bottlenecked case that operates at redline. Touch it off, and the case will expand to fill every nook and cranny in the chamber. Squeezing it back down to be able to be chambered again moves a lot of brass. Cases “grow” or lengthen in a resizing die—which is why they need to be trimmed occasionally—and the movement occurs just ahead of the case web. I check every bottleneck case with my paperclip feeler gauge at every reloading. When I feel a discernable dip just forward of the bottom of the inside of the case, I scrap it. Sure, I can probably get one, perhaps two more loadings out of it. Equally possible is that the head will separate during the next firing, and I will be left with an unusable gun in my hands until I can arrange to get the forward portion of the case removed from the chamber.

Does that mean that the .38 Special is a better cartridge than the .300 RUM? Of course not. The two are made to do different things. The .300 RUM is a superb hunting cartridge that performs at a very high level. Performance—whether in a firearm or a hot rod automobile—comes at a price.

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