Need help reloading 6.5CM... Case head separation

[fguffey]

Start over every day:

Reloaders are supposed to know what they are doing, insulting me does not convince me the reloader knows or understand he knows what he is doing.

I understand component manufactures do not provide components for reloaders that have taken the short-cut path to reloading like moving the shoulder back, bump the shoulder back etc.

I have never seen it written nor have I heard a reloader explain to another reloader long cases are available at the firing range. There was a time I would take my ammo, rifles and case length measuring tools to the range to find long cases. My long case measuring tools measure the length of the case from the datum to the case head. My favorite cases were cases that were fired in trashy old chambers, I would go through thousands of cases to match head stamps, there were times I would match cases and headstamps that would convince me
I matched 20 fired cases to the same box.

And then there is the old fairy tale about every case stretches between the case head and case body; again, I have fired cases in chambers that had .127" clearance without case head stretch and or separation. All that happens every time is the case shortens between the end of the neck and case head. Shortens how much? The cases are ejected after firing with no necks and a very short shoulder.

A lot can be said for measuring before and again after firing, but I find it a waste of time mentioning it here.

F. Guffey

[divingin]

And then there is the old fairy tale about every case stretches between the case head and case body

Well, everything is a fairy tale if you don't adapt to using common language. We use terms like headspace, clearance, datum, etc, and you're the only one who balks. You ever get the feeling that this may be your problem more so than the rest of the shooting community?

All that happens every time is the case shortens between the end of the neck and case head. Shortens how much? The cases are ejected after firing with no necks and a very short shoulder.

I've seen that happen when shooting the wrong cartridge in a rifle. Are you promoting this kind of practice?

A lot can be said for measuring before and again after firing, but I find it a waste of time mentioning it here.

Anyone who measures a cartridge before, and after, loading it (which I think a majority of serious reloaders do) is doing just that. They just do it at home rather than at the range.

[fguffey]

I've seen that happen when shooting the wrong cartridge in a rifle.

I've seen that happen when shooting the wrong cartridge in a rifle. Are you promoting this kind of practice?

No, I thought I would save a few reloaders a little time, it seems many of them start over every day, they start with fire forming, with unknow chambers I start with forming the case first and then firing. I could ask "Where does a reloader find cases that are longer than their chamber from the datum to the case head"?

All I want to do is cut down on all that case travel. Try to remember there are chambers that are belted for belted cases, there are chambers that are designed to fire cases with rims. And then there are control feed rifles and there are push feed rifles.

F. Guffey

[fguffey]

A lot can be said for measuring before and again after firing, but I find it a waste of time mentioning it here.

Anyone who measures a cartridge before, and after, loading it (which I think a majority of serious reloaders do) is doing just that. They just do it at home rather than at the range.

I will type slower for you; there was a time I purchased fired cases from the range (typing slower) because component manufacturers did not and do not sell cases to reloaders that know what they are doing. My favorite cases are cases that have been fired in trashy old chambers (trying to type slower) because I know most of the cases I purchase from the range will not chamber in my rifles without sizing the cases.

The worst habit I could get into starts with adjusting the bottom of the die to the shell holder when I start. I have a M1917 that has a chamber that is .016" longer than a minimum length/full length sized case. Based on your last response I will make a wild guess and say you have no clue what I am talking about. And then there is the other point you missed; the fired 30/06 cases from my M1917 would be the perfect case for sizing cases for my long 30/06 chambers.

And then? There is the point you missed, or you have a big problem with reading and comprehending, my 30/06 cases fired in my M1917 cases get longer from the shoulder/case body juncture to the case head without stretching between the case head and case body.

As the reloaders says, "If I die before I wake, no problem, I get more sleep."
I do not expect you to understand but if my case stretches between the shoulder and case head when I fire it, no problem, I get more room for powder.

F. Guffey

[fguffey]

So I guess my question is how much of a headspace gap is too much? Should I buy a set of go no go gauges to see if my rifle has an out of spec chamber? Anyone ever have issues with the dies and Dillon lube? Any help is appreciated I'm really at a loss right now!

Matt, worrying about the length of the chamber from the datum to the bolt face
is something you should have concerned yourself with after the first firing. You should know the length of the chamber by the time you fired the rifle 80 times.
Or you should know the effect the chamber had on the case when you fired it.

F. Guffey

[fguffey]

I buy a set of go no go gauges to see if my rifle has an out of spec chamber?

I have the ability to measure the length of a case from the datum to the case head so I will say I do not need a go-gage or a no go-gage or a field reject length gage.

You could purchase the three head space gages, after purchasing the gages you will need to find someone that can explain how to use them. Me? I want to know the length of the chamber from the datum to the bolt face; I do not want to know if the bolt will close on a no go-gage.

But if the bolt does close on the no go-gage I want to know by how much.

F. Guffey

[LynnJr]

New brass usually takes 2-4 firings before its tight in the chamber depending on your loads pressure.
All that means is if you neck sized only you wouldnt have to bump the shoulder or base for 2-4 reloadings.

To set up your dies lay the rifle in your lap and size most of the neck only but dont bump the shoulder.
If the brass chambers smoothly you are all set.
If it doesnt chamber smoothly turn the die further down in 1/4 turn increments until it cycles smoothly and you are now all set.

Dents in the shoulder or scallops can be excessive lube or it can be that you are pushing the shoulder too far back. They will both cause those dents or scallops on the brass.

If you push the shoulders too far back and want to avoid early casehead separation simply expand the necks using an expandiron made by k-m and create a false shoulder on the case neck so the brass cant move forward when struck by the firing pin.
You want to lock the brass into the chamber so it only expands outwards and doesnt try to lengthen itself.

If you set everything up correctly and the caseheads separate its most likely a fat chamber or skinny brass. You dont want excessive expansion of the brass near the caseheads and skinny brass and/or a loose chamber will cause this issue.

[fguffey]

So, I guess my question is how much of a headspace gap is too much?

Headspace gap? All of my chambers have clearance, it is possible to have .000 clearance or no clearance.

F. Guffey

[Wykyd]

New brass usually takes 2-4 firings before its tight in the chamber depending on your loads pressure.
All that means is if you neck sized only you wouldnt have to bump the shoulder or base for 2-4 reloadings.

To set up your dies lay the rifle in your lap and size most of the neck only but dont bump the shoulder.
If the brass chambers smoothly you are all set.
If it doesnt chamber smoothly turn the die further down in 1/4 turn increments until it cycles smoothly and you are now all set.

Dents in the shoulder or scallops can be excessive lube or it can be that you are pushing the shoulder too far back. They will both cause those dents or scallops on the brass.

If you push the shoulders too far back and want to avoid early casehead separation simply expand the necks using an expandiron made by k-m and create a false shoulder on the case neck so the brass cant move forward when struck by the firing pin.
You want to lock the brass into the chamber so it only expands outwards and doesnt try to lengthen itself.

If you set everything up correctly and the caseheads separate its most likely a fat chamber or skinny brass. You dont want excessive expansion of the brass near the caseheads and skinny brass and/or a loose chamber will cause this issue.

Thank you I appreciate the reply. I have been reading a lot and made a few changes in my reloading process. hopefully I can get back out soon and do some more testing.

[ar15barrels]

If it doesnt chamber smoothly turn the die further down in 1/4 turn increments until it cycles smoothly and you are now all set.

1/4 turn increments of 7/8-14 threads are over 0.018".

I recommend making 10 degree adjustments.
10 degrees on 7/8-14 threads is 0.002".

Even easier is to make 0.001" adjustments by wrapping some mm marked adhesive tape around your 7/8" threads to create a repeatable adjustment scale that reads out in 0.001" adjustment marks.

https://www.ebay.com/itm/203958055313

You cut off the inches and the CM markings so you just have a scale of 1mm marks and the 1mm marks will equate to 0.001" adjustments on 7/8-14 threads.
The tape has to be wrapped around the threaded portion, not the lock nut or the knurled or smooth sections of the die above the threads.
I recommend wrapping it maybe 1/8" above the lock ring so you can use the split on the lock ring as your adjustment reference.
If your lock ring is not split, make a sharpie mark on the top of the ring.
When you adjust your lock ring on your die, each park you pass means the die has moved 0.001" up or down on the die depending on which direction you are adjusting of course.

[Wykyd]

1/4 turn increments of 7/8-14 threads are over 0.018".

I recommend making 10 degree adjustments.
10 degrees on 7/8-14 threads is 0.002".

Even easier is to make 0.001" adjustments by wrapping some mm marked adhesive tape around your 7/8" threads to create a repeatable adjustment scale that reads out in 0.001" adjustment marks.

https://www.ebay.com/itm/203958055313

You cut off the inches and the CM markings so you just have a scale of 1mm marks and the 1mm marks will equate to 0.001" adjustments on 7/8-14 threads.
The tape has to be wrapped around the threaded portion, not the lock nut or the knurled or smooth sections of the die above the threads.
I recommend wrapping it maybe 1/8" above the lock ring so you can use the split on the lock ring as your adjustment reference.
If your lock ring is not split, make a sharpie mark on the top of the ring.
When you adjust your lock ring on your die, each park you pass means the die has moved 0.001" up or down on the die depending on which direction you are adjusting of course.

That is an awesome idea thank you sir!

[fguffey]

That is an awesome idea thank you sir!

I did not believe there was anything awesome about cutting out paper doilies for indexes today than when Uncle Nick made the suggestion years ago.

If the thread count on the die was 10 threads per inch, 1 complete turn of the die would be .100" or 1/10 of an inch; the thread counts on the die and press is 14 threads per inch meaning 1 turn of the die is equal to.072" + a few per turn. And then there were those that wanted to use the fractional turn of the die. Nothing for a reloader to keep up with but 1/4 turn of the die is equal to .018".

I suggested reloader learn to use a height gage or a feeler gage, I never thought there were reloaders that could not measure protrusion. I should have known better; there was a disagreement between smiths at an arsenal back in the 1940s that turned smiths against a smith, he was one of those smiths that did not take long to look at something when figuring 'it' out'. The other smiths were tacky talkers, they just simply could not determine what and or how he was doing it.

F. Guffey

[smoothy8500]

I'm never disappointed when I tune in for the "pearls" of wisdom sprinkled with an occasional cool story...

[fguffey]

If the brass chambers smoothly you are all set.
If it doesn't chamber smoothly turn the die further down in 1/4 turn increments until it cycles smoothly, and you are now all set.

1/4 turn? And then he added increments. If the die has 14 threads per inch, a 1/2 turn of the die is .03570", 1/4 turn would be .01785". I will say, think about it, it seems like a conflict with reloaders that claim they have been reloading for 65 years and we have reloaders that claim they make 1/4 adjustments (increments) when adjusting for smooth bolt close.

And then I will say think about it again; .01785" is .00385" longer than a field reject length gage for a 30/06. I have a M1917 that has a chamber that is .002" longer than a field reject length gage. I could ask about how much clearance would I have if I chambered a full-length sized/minimum length round in my M1917?

F. Guffey