Case head separation query

[charlie b]

RCBS X die or small base dies. Or, just have a custom die made. A few mfgs will set up a die based on your fired cases.

 

[divingin]

Ooohhh, an even quicker method for a point. The point helps with feel. I touched my clip end to a bench grinder to make a point. Been using it for a long time & it still works perfectly. Hangs from a small nail in easy reach.

It really does look like marks from the cartridge box in the OP.

I usually have 4 or 5 sharpened formed paper clips in my rifle box. They get given away at the range to those who may be having problems. Just another one of those items I carry for others (another example is a AR front sight tool - I haven't shot an AR in over a decade, but have the tool for people that do.) And I wonder why my box is so heavy...

 

[Dufas]

Cut one open and check it that line is where case separation occurs. And size your cases to HS properly.

 

[jelenko]

Just because it’s not necessary, does not mean it’s not beneficial.

Long before the buzzword phrase of “excessive shoulder bumping” became an internet sensation, it was called “ following the directions of the dies manufacturer”. The directions generally sized the case to minimum spec for the cartridge to fit in a chamber sized for maximum spec brass. Fully resizing the case to as new size. The problem is that “as new size” in a minimum chamber is often the leading cause of short brass life by losing your casehead.

Once people figured out that if they didn’t fully resize their brass, not only did case capacity went up, increasing velocity, accuracy but case life improved. All you had to do was set the die up to just, touch, kiss or bump the shoulder. It didn’t need to be pushed back where it came from, only reminded not to go any further.

The problem with just bumping the shoulder with an off the shelf die, is that the base is no longer fully resized. Which if ignored, will lead to another internet sensation called a “clicker”.

Clickers are evil and can happen for a couple reasons. Often because you can’t just bump the shoulder and resize the base at the same time. That mostly needs a custom die matching your chamber, or the nearly outlawed practice of neck sizing only. Here we should probably split clicker into two different categories or call one a clacker.

If a clicker is because a case head is too fat, a clacker is because the body is too long. Both can make the bolt hard too rotate. To know which you have you have to be able to distinguish between a clicker and a clacker.

The cure for clickers and clackers is the same. Apply more sizing. But be careful not to apply too much resizing, remember you just need to bump the shoulder, not push it. Because if you push it too much and too often, you can lose your head. I mean case head. Which you probably deserve to have happen anyway because, anyone who has their head stuffed up under their body at the opposite end of their neck and shoulders has an obvious problem.

So here’s the dilemma , many of the really experienced guys that shoot really small groups and or high scores, recommend full length sizing and minimum shoulder buzzword. This is absolutely impossible with a single off the shelf die. To get the base, the shoulder is in the wrong place, too much headspace when chambered. To size for minimal headspace, the base may not chamber or extract easily because it’s too fat.

Bottom line is that what we really need is a new buzzword for squeezing the case head down to a smaller diameter. Choke your casehead probably won’t work, maybe hug?

Things were so much easier when people reloaded to save money over factory ammo. Once people wanted better accuracy, it required the adaptation of buzzwords. Next thing you know there will be some of those confusing acronyms.

Somebody's on a tear today.

 

[RegionRat]

I realize that not everyone grows up in a metalworking environment and has the tools and experience to section a case.

It may take some investment and practice to be able to produce a lab quality section, but it isn't expensive or difficult to learn to section one to check for ICHS in this context.

You can do this on your own with common household tools. There are many ways to do this depending on what you have available. If you have absolutely nothing, you probably have a neighbor who can help.

It doesn't have to be lab quality, it doesn't have to be pretty, it just has to answer the question is the case starting to fail.

 

[searcher]

Apparently you either didn't read my entire post or didn't understand it. I was very specific about what the purpose of "shoulder bumping" is and that it needs to be measured and done minimally. You say it's not "necessary", well use a neck die 4 or 5 times on a group of cases and see how many of them you can't close the bolt on. What in my post gave you the idea that I suggested doing anything "Willy-nilly"??? Everything require precision measurement.

The last line in your response totally mystifies me "Maybe the goal is to work the brass as much as possible...", because I specifically said if you bump the shoulder the way I suggested, you won't over work you brass! In your next post you talk about if you can't close the bolt then you need to trim the neck because the brass is too long - maybe, but we aren't talking about OAL here we are talking about base to shoulder length.

I honestly don't know why you decided to make this a pissing match. Controlled "shoulder bumping" is acknowledged by most everyone I read and respect as advisable if not necessary.

I can't even believe folks argue over the need to bump. We all (?) know that folks can go without bumping until, as you say, the bolt will simply not close. Sometimes, that can take anywhere from 2 to maybe 6 or more firings. But - in the end - it will require the bump. The approach that seems to be the most universally accepted is to not bump until it is known that the brass has filled the chamber - then do a very slight bump on every loading thereafter. On a bolt gun (for precision), we might be talking just enough to still feel a slight resistance when the bolt is almost closed. Many folks cite .003" to .004" for semi's, as though they anticipate harsh battle -type conditions and handling. I typically go no more than .002" in a semi. Whether bolt or semi, the more one bumps, the more cases stretch, get trimmed, and the faster case separation will occur - assuming the pockets or necks don't go first - whether it is 10 loadings or 50. A slight bump does not overly work the brass, though if using a really badly fitting die, that could happen. I've done it both ways - neck sizing only and no bump till absolutely needed - and bumping slightly after each firing. I have noticed no shortened lifespan from my brass while bumping. The results of others many differ....