August 4th 2023Have you ever wondered what caused an unusual bulge or mark on a case. Is the case safe to use after the issue? Sierra Bullets Ballistic Technologist Duane Siercks provides some insight into the causes of various issues in two Case Diagnostic articles on the Sierra Blog.This Winchester.308 Win Case has a serious issue. This case is in the process to fail completely due to a very visible incipient separation of the case head. This is usually caused by an over-sized case that has excess headspace. This case is almost ready to fall apart after a few firings. Die adjustment is a must here. This case is not suitable for reuse.
There are two pressure indicators to be aware of in the image of the case rim. Look at the primer first. It is flattened about as far as it can be considered safe. If this was the only sign of pressure, I would be fine with this weight, but I would keep a close eye on it, especially if this load was to be used in warmer temperatures. This load can easily cross over into the “excess” pressure realm very quickly. There is another sign of tension that we cannot ignore. You’ll see that there is a visible ejector mark located above the “R” in the R-P head stamp. This tells us for sure that the load was not within the safe pressure range. If any of these rounds were loaded, they should be disassembled and not fired. This case should never be reloaded. Split Case-Neck
This is a R-P.22250 case that has been killed. This case looks good except for the split neck. This case should be thrown away. A split neck is something that happens all the time. This is caused by the work-hardening. Brass cases become harder with age and usage. After a long period of storage, brand new brass cases can become so hard that they will split in one or two firings. I’ve seen new factory loads do this. As we resize these cases and fire them repeatedly, they tend get harder. They will eventually split. By carefully annealing the case, you can extend its life. This issue would require its own article. In my classes, I use examples like this one to show students what to look for. As always, if we can assist you, whether you are new to reloading or very experienced, contact us here at Sierra Bullets by phone at 1-800-223-8799 or by email at sierra@sierrabullets.com.Dented Case Body
This is a Lake City 7.62×51(.308 Win. ) This case has two heavy marks/dents on the case body. It may be a mystery. This case appears to have been caught by a semi-auto gun when it jammed, or failed to clear the cycle. I would not reload the case to avoid any feeding issues. Multiple Problems — Lake City 5,56×45 unknown years. This case has experienced multiple failures and can’t be re-used. It has a very rounded and split shoulder. It was immediately apparent that this round had been the victim of excessive pressure. The firearm (perhaps an AR?) The firearm (perhaps an AR?) was not fully charged or there could have been a problem with the headspace. When I looked closer, the primer was very flat. The outside radius of primer cup had also been lost. High pressure! Then I noticed that the case rim had an ejector marking. This is definitely an instance of excessive pressure. To see more examples, you can view Part I and II of the Sierra Bullets Case Diagnostics. It is important to inspect and observe your cases before every reload. After a while, it becomes second-nature to notice the small things. As you become more comfortable with the reloading procedure, don’t get complacent. Sierra’s Techs can be reached at 1-800-223 8799 if you are ever in doubt.
Similar PostsTags: Bulged Cases Case Diagnostics Case Separation Flattened Primer Pressure Signs Sierra Bullets Split Case-Neck
