Is this Case Separating?

[Metal god]

I buy once fired cases from my local range . They come incredibly dirty . They often are very tarnished with rocks ,twigs and other smaller cases inside them .

These cases "MUST" be cleaned before any prep work starts . I get what you're saying RC20 and I have on more then a few occasions skipped tumbling before sizing my own once fired cases because they never hit the ground and are still pretty clean .

That said there are plenty of reasons why one would need to tumble cases before doing anything else with them . Lets not act like there's no reason for this step at times .

[Longshot4]

I agree with Metal God... Salvaged brass requires a good cleaning first.

[Longshot4]

I agree with Metal God... Salvaged brass requires a good cleaning first.
Right down to the primer pockets and uniformed pockets.

[F. Guffey]

These cases "MUST" be cleaned before any prep work starts . I get what you're saying RC20 and I have on more then a few occasions skipped tumbling before sizing my own once fired cases because they never hit the ground and are still pretty clean .

R. Lee in his book on modern reloading has a section of case cleaning. I do not agree but according to him it is not necessary to clean brass before sizing.

I am the fan of having nothing between the case and chamber but air, I do not want a lot of air but the air between the chamber and case must be clean; no matter how much effort is put into cleaning cases the firing range is not a clean environment and the case is embeddable meaning anything that is between the case and chamber is embedded into the case when fired.

I do not want my cases sliding in the chamber with embedded dirt, grit and grime, I do not want all of that embedded dirt, grit and grime taking the shiny finish from the inside of my dies so I choose to have nothing between the case and chamber but air, that goes for my dies also, I want clean air and lube when sizing.

Back in the old days of wagon trains they kept a bucket of greases on the side of the wagon, the worst thing that could happen to the grease is to leave the lid off of the bucket because the environment around that wagon and wheels turning stirred up a lot of dirt, grit and sand. And then there were brakes, wagons had two types.

F. Guffey

[Reloader270]

My 270Win leave this same mark on cases after the first reload. Some of the cases has been reloaded 10 times and case head separation had not appear. I have done the paperclip test several times and there is no indent on the inside.

[F. Guffey]

This is getting very complex Mr.Guffey

If the case is FL sized to a length less than the distance from the bolt when closed too the chamber shoulder or is it datum? "In a 308" The case is expanded do to the pressure of the powder charge in all directions. It's stretched out to the chamber walls, back to the bolt face and forward to the chamber shoulder that acts as a gas check and the neck to the chamber neck walls. So if you resize the case to a shorter length. It will stretch to a longer length. That is what causes (Metal God) to give us a fine picture for reference.

In that case we get stretching along with thinning of the case as metal god shows in his picture.
The stretching of the cases from metal god's picture are from excess head space I believe. What happens is the head stays against the bolt face and the shoulder of the case is driven to the shoulder of the chamber when the cartridge is fired. If the gap is more than 0.002-3K That's where the case will stretch and if continues case will separate. That's where you want to just bump the shoulder 0.002-3K when Full Length sizing.

The first time around you start with "What happens"' the case head is against the bolt face and the shoulder moves, the case is driven forward. I have said many times if the case head is against the bolt face and the shoulder 'MOVES forward and then there is nothing after that because that is not what happens.

I said I chambered a round in a rifle and pulled the trigger, after pulling the trigger I said the shoulder did not move even thought the shoulder of the case was .127" from the shoulder of the chamber... According to reloaders a case will not stretch .127" without case head separation. Reloaders everywhere say head space is the cause of case head separation and then I said there has to be something about the sequence of events between pulling the trigger and the bullet leaving the barrel reloaders do not understand.

I took the time to paste your quotes from two different responses, the two quotes are different. My opinion; ever reloaders on this forum should have noticed.

It took me many years to eventually understand it all. That is if I do.

Longshot4, have MG explain it to you. You said the shoulder moved, I ask "How is that possible?", I ask because you said the case head was against the bolt face.

Case head separation: I have managed to destroy cases in a 30/40 Crag, the rifle was part of an inheritance. After testing the rifle I had the new owner promised me he would not fire the rifle. A smith in Colorado sent me a receiver; problem, replacing the receiver on a rifle your grandfather left you would not be the same rifle.

F. Guffey