Case head separation?

[CptDan]

Couple of things that cause case head separation, too much shoulder bump or the headspace is not correct. You need to be measuring your fired cases to the datum line which means getting a Hornady checker and a good Vernier Caliper. Measure the fired case, measure a resized case.

[fguffey]

Couple of things that cause case head separation, too much shoulder bump or the headspace is not correct. You need to be measuring your fired cases to the datum line which means getting a Hornady checker and a good Vernier Caliper. Measure the fired case, measure a resized case.

the reloader should be measuring the length of the case from the datum/shoulder to the case head on cases before firing and again after firing. The reloaders should learn to measure the length of the chamber from the shoulder/datum to the bolt face.

Vernier Calipers have lost favor with reloaders, they prefer the dial indicator. I disagree with the Hornady comparator. The Hornady comparator requires the reloader to measure the case before and again after.

The Wilson case gage is a better choice, it is a datum based tool.

Hatcher thought he had head space figured out; to prove it he increased the length of the chamber by .060". After reaming he chambered a minimum length/full size round into his modified chamber. After ejecting the fired round he found he was wrong. The additional .060" clearance when added to the .005"+ clearance did not cause a head space separation. He could have prevented a lot of confusion had he determined what happen to the case when fired.

F. Guffey

[smoothy8500]

The additional .060" clearance when added to the .005"+ clearance did not cause a head space separation.

I've seen similar examples where inattentive shooters chambered and fired 308 Winchester rounds in 30.06 rifles. You are correct that aside from blown-out shoulders, no case separations occurred.

Of course, anecdotal incidents do not prove anything for certain.

[fguffey]

I've seen similar examples where inattentive shooters chambered and fired 308 Winchester rounds in 30.06 rifles. You are correct that aside from blown-out shoulders, no case separations occurred.

Of course, anecdotal incidents do not prove anything for certain.

Firing the 308 W in the 25/06 chamber could have caused death to the shooter. The 308W case head spaced on the shoulder of the case. The shooter had to force the 308W round into the 25/06 chamber; the shoulder diameter of the 308W is .014" larger in diameter than the chamber of the 25/06 at the point of contact.

I did not suggest the shoulder blew out when it formed to the chamber, the 308W case became part of the rifle. It took 2 hours to remove the case. The case head was hammered so hard the case head stamp no longer existed. The smith had to have the shooter retrieve the receipt for the ammo he purchased in attempt to determine what the shooter chambered.

My opinion; had the shooter purchased good bullets the rifle would have been rendered scrap. Smiths in the area were guessing how long the bullet was when it left the barrel. For the bullet to leave the barrel it would have had to be swaged down .058" in a hurry. When the bullet hit the rifling the bullet became a plug with no time to leave etc. etc.

When the 308W is fired in the 30/06 the case head spaces on the shoulder of the 30/06. Time allows pressure to escape past the bullet before the bullet hits the rifling. The bullet gets past the rifling because of the running/jump start. The case is ejected with the hint of a shoulder because of case expansion.

I know reloaders have a real problem determining the direction of shoulder travel when sizing and or firing. The shoulder of the 308W became part of the case body. Again, there was only a hint of a new shoulder, that would be two shoulders; the one the shooter started with and the one the shooter finished with.

F. Guffey

[fguffey]

I did not suggest the shoulder blew out when it formed to the chamber, the 308W case became part of the rifle. It took 2 hours to remove the case. The case head was hammered so hard the case head stamp no longer existed. The smith had to have the shooter retrieve the receipt for the ammo he purchased in attempt to determine what the shooter chambered.

The smith could have asked for the box of 19 rounds the shooter did not shoot because the first round stopped all activities. Instead he asked for a receipt thinking the shooter could have asked for 25/06 ammo but was sold 308W. I know there are bar codes but the smith was not going to play a part in a law suit. The receipt read 308W.

The shooter did not know how the rifle was chambered, it was not his rifle.

F. Guffey

[divingin]

the reloader should be measuring the length of the case from the datum/shoulder to the case head on cases before firing and again after firing.

[snip]

I disagree with the Hornady comparator. The Hornady comparator requires the reloader to measure the case before and again after.

Ummm, what?

You're saying you should measure the CBTD before and after firing, but don't like a tool that requires you to measure CBTD before and after firing?

[divingin]

When the 308W is fired in the 30/06 the case head spaces on the shoulder of the 30/06.

Does it? Or is it held against the bolt by the extractor? If the 308 does headspace against the shoulder of the -06 chamber, how does the firing pin hit the primer?

[fguffey]

Ummm, what?

In the beginning I thought reloaders were capable of measure the length of the case from the datum to the case head because I thought reloaders could make a tool designed to measure the length of the case from the datum to the case head. I was wrong.

I thought reloaders read the instructions furnished by the manufacturers with the tool, again I was wrong. Reloaders in the beginning thought the datum was a line with an arrow pointing to 'it'.

In about 1938 L.C. Wilson started selling case gages, I had no ideal there was more information available in the instructions than reloaders could handle. The Wilson case gage is and always has been a datum based tool. Problem, for 40+ years the reloader used the case gage as a drop in (plop) gage.

Anyhow, I have instruction for the case gage, my instructions suggest the user/reloader use a straight edge. Little did I know the reloader did not know and or understand what a straight edge was. In the old days I carried a pocket rule, the pocket rule is a straight edge, and I work off of tables and hard surfaces tables have flat surfaces, a flat surface is a straight edge. It was about that time I started using a feeler gage to measure the distance from the straight edge to the Wilson case gage BECAUSE the case gage had two heights. One height was minimum length and the other height was go-gage length.

The Hornady tool you are referring to had a flawed datum. The Hornady/Sinclair comparator datum has a radius. My datums to not have radiuses, my datums have a sharp edge. Because? I want to zero my tools, I want to verify my gages.

Hornady/Sinclair comparators owners have to purchase a tool to very the gage because of the radius. I understand, none of this makes any sense to a reloader but the Wilson case gage is a datum based tool with a radius. not a problem because Wilson built the tool to compensate for the error.

I took the first Wilson case gage to the bench and checked it out to see how it worked. A block of lead, case, drift and hammer. I know, some are chamber casters, I was finished before they could find a torch.

If I made a case of the Wilson case gage I would finish with a casting that was go-gage length or minimum/full length size from the datum (with a radius) to the case head.

F. Guffey

[pacrat]

Does it? Or is it held against the bolt by the extractor? If the 308 does headspace against the shoulder of the -06 chamber, how does the firing pin hit the primer?

An astute question that takes into consideration "case length" from base to datum of each.

But ignores the compounded asininity that lead to it.

I've seen similar examples where inattentive shooters chambered and fired 308 Winchester rounds in 30.06 rifles.

When the 308W is fired in the 30/06 the case head spaces on the shoulder of the 30/06.

Considering the diametric dimensional conflict of case diameter reality.

How can a person firing a rifle be "inattentive" while either repeatedly slamming the bolt forward? Or beating on it with a hammer? In order to get it to close, on a cartridge that is to FAT to FIT??

And how can the self professed "Guru of ALL Things Reloading" be so ignorant to not know what he claims is not just improbable? But impossible?

[fguffey]

Originally Posted by divingin View Post
Does it? Or is it held against the bolt by the extractor? If the 308 does headspace against the shoulder of the -06 chamber, how does the firing pin hit the primer?

The shooter sized the case when he chambered it. He did not hurt himself with heavy work he simply crushed the case at the shoulder/case body juncture.

The shooter wrote an article about his experience at one the famous matches. He was shooting an M1 Garand. The bolt closing was enough to size the case body before the bolt closed. The ejected case only had a hint of a shoulder; what does that mean?

F. Guffey

[fguffey]

How can a person firing a rifle be "inattentive" while either repeatedly slamming the bolt forward? Or beating on it with a hammer? In order to get it to close, on a cartridge that is to FAT to FIT??

And how can the self professed "Guru of ALL Things Reloading" be so ignorant to not know what he claims is not just improbable? But impossible?

Pacrat, why are you so angry, the man behind the rifle was Major Dick Culver of the SCP shooting page. He did not complain about the accuracy but realized something went wrong after he examined the cases.

When the 308W is fired in the 30/06 the case head spaces on the shoulder of the 30/06.

The 308W case head spaced on the chamber of the 30/06; again, the 308 W case is larger in diameter than the 30/06 chamber at the point of contact by .014".

F. Guffey

[fguffey]

And how can the self professed "Guru of ALL Things Reloading" be so ignorant to not know what he claims is not just improbable? But impossible?

It should be very clear to a reloader the taper of the 308W case is less than the taper of the 30/06 chamber. If you were not so angry and were able to remove your fingers from the keyboard and had the ability to imagine or had a fundamental understanding of mechanical drawings etc. etc.

The information furnished by Dick Culver has been available for over 15 years. The CSP forum was a socially dysfunctional forum. There were a lot of angry people on the forum and there were many that were starving for attention.

F. Guffey

[smoothy8500]

How can a person firing a rifle be "inattentive" while either repeatedly slamming the bolt forward? Or beating on it with a hammer? In order to get it to close, on a cartridge that is to FAT to FIT??

A Garand does a pretty good job of closing on a 308W cartridge. I agree that if the shooter was trying to chamber it on a bolt-action he would have definitely jammed the round and figured something is wrong.

[fguffey]

Couple of things that cause case head separation, too much shoulder bump or the headspace is not correct.

Pacrat, I can only imagine you have no clue what CptDan is talking about, I do not know where CaptDan gets his information. Seems reloaders can throw in the word 'bump' and then qualify as an expert reloader.

Pacrat you spend too much time snarling at people you do not agree with. CaptDan explained everything with 'Bump' and then went straight to 'head space is not correct'.

Hatcher thought he had a good grip on head space, to prove his theory he increased the length of a 30/06 chamber .060", for those that can keep up that would be .065" clearance between the shoulder and case head when fired. I do not know what CaptDan considers head space but Hatcher's cases did not suffer case head separation. According to CaptDan case head separation is caused by incorrect head space. On Hatchers rifle the chamber was .005" longer from the shoulder to the bolt face than the case when measured from the shoulder to the case head. And then Hatcher increased the length of the chamber .060" from the shoulder of the chamber to the bolt face.

Same old thing: I purchased a M1917 rifle, I checked the length of the chamber, The length of the chamber was .016" longer than a minimum length/full length case or .002" longer than a field reject length chamber.
Fix it? I formed 30/06 cases from 280 Remington cases, I added .014" to the length of the cases, for those that can not remove their hands from the keyboard that left me with .002" clearance.

The 280 Remington case is .051" longer from the shoulder to the case head than the 30/06 case. With .051" I did not loose any bullet hold because of a short neck.

CaptDan and head space not correct: I went to the range with 2 Mausers with 8MM06 chambers. Thinking about Hatcher, he increased the length of his chamber .060". I increased the length of my 8MM57 chambers .127". I chambered 8MM57 ammo in my 8MM06 chambers. Nothing happed, the head space was not correct. When I ejected the fired cases the cases told the story, I can see where an angry person would scorn the day he ever learned to load; that is not me, I looked at the cases and immediately understood what happened. Bump and incorrect head space did not cause the cases to have case head separation.

For me it is like a reloader examining hot horse shoes, it does not take me long to look at it. I did not spend all of my time with my hands on the keyboard. I am the one that has 3 RCBS Rock Chuckers that do not cam over;

I am the one that has at least 14 Herter presses, all of my Herter presses cam over, my Herter presses are called 'bump' presses.

F. Guffey

[MarikinaMan]

Take a paper clip and bend it into an "L" shape with a short horizontal leg. Use it to feel for a groove on the inside of the case. You can also Dremel or band saw one of your cases to check the inside for thinning. I doubt you will find it in your situation. If in doubt, throw it out, but you are probably OK.

^^^this.

another possible cause is that the die is biting into overly expanded cases. I recently reloaded some range pick ups that were really expanded, and the die would dig into the brass and cause rings like that. after getting fired, they could possibly look like that. I tossed them though.