Hydraulic case forming

Please share with us your calculations or source

I have now discovered that the pressure needed to fire-form brass is 12,000.00 psi
According to the MS calculator = 827.37084 BAR
Still a lot ...

https://www.azom.com/article.aspx?ArticleID=6341

Print it out and ask your workshop buddy to interpret.

The property you are looking for is called "yield strength". Also known as the elastic limit. That depends on the temper of the brass.

I see this also explained here ...

The Truth of the Myth

https://www.azom.com/article.aspx?ArticleID=6341

Print it out and ask your workshop buddy to interpret.

The property you are looking for is called "yield strength". Also known as the elastic limit. That depends on the temper of the brass.

Cartridge makers like Norma and Lapua manipulate the temper of the brass they use to get as close to full-hardness at the webb and and around 1/4 temper at the neck and shoulder. Kan be as soft as 20 ksi for the neck to 65 ksi at the web area. The softer the material the less springback you get and the more difficult it becomes to extract.

There is a reason why rifle calibers are all below 65 ksi pressure rated.

Thanks
Did you check and measure your brass at the web ?
Before firing / after firing / after reloading
Did you check and measure you FL sizing die ?

IS there any movement at the web ?

I would suggest that this is a rough method that some use to check for pressure signs

I am interested to know - IF this area is sized at all in the FL sizing process ?

IF so how much pressure you are exerting with your reloading press - 65ksi ?

The components used for fire forming are only expensive if you waste them.

My idea of fire forming, barrel break-in etc is to make a useful load and actually do something useful while doing these operations. There is no reason a fire-form load can not be used on a target or even a varmint or game animal in the field.

It would be interesting to take twenty good factory rounds and put them on target at 100m - with a chronograph
Then take twenty rounds to be fire formed and do the same ( of course it depends on what it is you are trying to fire-form )

I wonder what you would see / learn ?

IF in the US ( and wealthy ) this is what you do ...

Greetings
I am sure most people know about hydraulic case forming using a special die and water to form cartridge cases
Rather than the normal fire-forming which uses expensive components.
The hydraulic method can however potentially be a bit messy

I wonder if anyone has looked at using a - Pneumatic process to do the same work ?
Would be a lot cleaner and not messy
Should not be too difficult to make the necessary parts ?
I do wonder what kind of air pressure you would need though ?
300 Bar is not unusual in some engineering processes.

The components used for fire forming are only expensive if you waste them.

My idea of fire forming, barrel break-in etc is to make a useful load and actually do something useful while doing these operations. There is no reason a fire-form load can not be used on a target or even a varmint or game animal in the field.

https://www.azom.com/article.aspx?ArticleID=6341

Print it out and ask your workshop buddy to interpret.

The property you are looking for is called "yield strength". Also known as the elastic limit. That depends on the temper of the brass.

Cartridge makers like Norma and Lapua manipulate the temper of the brass they use to get as close to full-hardness at the webb and and around 1/4 temper at the neck and shoulder. Kan be as soft as 20 ksi for the neck to 65 ksi at the web area. The softer the material the less springback you get and the more difficult it becomes to extract.

There is a reason why rifle calibers are all below 65 ksi pressure rated.

I worked in hydraulics and pneumatics all my life. Owned my own medium sized hydraulic and pneumatic company for over 30 years.

Thanks
Unfortunately no-one has yet clarified just EXACTLY how much pressure is needed to "form" brass a few thou mm
I can "form" brass using case lube in my LEE Challenger press - 300 Win Mag to 308 Norma Mag
Which involves relocating the neck and shoulder
However that is not going to help if you need to "blow-out" all the case dimensions ... a few thou mm

Before we - speculate can someone give a properly calculated answer as to exactly how much pressure is required to do this ?
I would suggest it is far BELOW the crazy pressures mentioned here ....

Happily none of my dreams were harmed by your post. A few of my nightmares may have been confirmed though ;)

Perhaps ?

Happily none of my dreams were harmed by your post. A few of my nightmares may have been confirmed though ;)

I worked in hydraulics and pneumatics all my life. Owned my own medium sized hydraulic and pneumatic company for over 30 years.
Nothing is impossible with enough money. However, nowhere in the world can you buy an air compressor that delivers 30000 psi. Someone, somewhere might be able to build one if you have a very big chequebook. 30000psi hydraulics is only available in specialised laboratory equipment, again at a horendous price.
You might be able to build something like this for a few million rand, perhaps.

Killer of dreams!

😂😂Now I'm hurt. 😂😂

I worked in hydraulics and pneumatics all my life. Owned my own medium sized hydraulic and pneumatic company for over 30 years.
Nothing is impossible with enough money. However, nowhere in the world can you buy an air compressor that delivers 30000 psi. Someone, somewhere might be able to build one if you have a very big chequebook. 30000psi hydraulics is only available in specialised laboratory equipment, again at a horendous price.
You might be able to build something like this for a few million rand, perhaps.

Killer of dreams!

I worked in hydraulics and pneumatics all my life. Owned my own medium sized hydraulic and pneumatic company for over 30 years.
Nothing is impossible with enough money. However, nowhere in the world can you buy an air compressor that delivers 30000 psi. Someone, somewhere might be able to build one if you have a very big chequebook. 30000psi hydraulics is only available in specialised laboratory equipment, again at a horendous price.
You might be able to build something like this for a few million rand, perhaps.

Right. Please place the link...

Ultimate Reloader

So, no pneumatic case forming? Not even in America?

How surprising...

Can be done at home, no.

Perhaps we should qualify that by saying .. not in SOUTH AFRICA

See Ultimate Reloader YouTube channel

Gavin Gear

But possible elsewhere ...

You ask a lot of questions for someone who has all the answers.

Answers are like decisions
Not all are the correct ones ...

Right. Please place the link...

Ultimate Reloader

Can be done at home, no.

Perhaps we should qualify that by saying .. not in SOUTH AFRICA

See Ultimate Reloader YouTube channel

Gavin Gear

But possible elsewhere ...

You ask a lot of questions for someone who has all the answers.

Right. Please place the link...

Can be done at home, no.

Perhaps we should qualify that by saying .. not in SOUTH AFRICA

See Ultimate Reloader YouTube channel

Gavin Gear

But possible elsewhere ...

Can be done at home, no.

Sounds like a solution looking for a problem and I still dont see any benefits to what you propose.

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Saving costs of components +
Cabe done at home +
Complexity -
Initial costs -
Potential safety issues -

Sounds like a solution looking for a problem and I still dont see any benefits to what you propose.

What could the possible advantages of using a compressible gas to do this work be over an incompressible liquid?

The water method as currently done by private individuals is messy and archaic
Hitting a ram ( plunger ) a couple of times with a lead hammer and making sure water does not spray everywhere is hardly an efficient or accurate process.
Perhaps the in-compressible liquid method needs a better worked out process with better equipment ?
Something an industrial process engineer needs to look at

The standard method of fire-forming IS a compressible gas expansion method - although the gas is in solid form
( the gas is produced by the oxidization of the propellant )

Perhaps one could use LPG instead of propellant for "fire-forming" ?

One needs to keep on thinking of different options and possibilities - otherwise we would still be using black-powder and round musket balls !

He thought that it might be possible - with a lot of problems that would have to be solved
The pressure spoken about here did not seem to scare him
I have not yet found out how much pressure you need to move cartridge case brass ( apart from the web and head ) a few thou mm ?
It might be in the realm of quite reasonable ?
The pressures generated by a normal discharge are what happens when the propellant ignites
To "form" the brass might not require anywhere near these sorts of pressures ?
A good engineer always designs a - well thought out pressure release / relief valve

What could the possible advantages of using a compressible gas to do this work be over an incompressible liquid?

If you are converting cases to a different calibre then such a procedure might be necessary.

Necking up / necking down are quite easy processes ( changing caliber )
Most people fire form when necks / shoulders and case taper are changed . modified = Ackley AI
or
When a new cartridge ( design ) is being made from an old one

With a chamber sizing reamer a gunsmith can make a FL sizing die from a blank.
Even without such a reamer IF one had a proper accurate chamber diagram , a good CNC operator on the correct machinery would be able to make you a FL die from a blank.
If the change was drastic you would need a form die - or perhaps two before getting to the final chamber FL sizing die

People who have old firearms for which factory brass is no longer available have to follow these procedures.

...

I will chat to my machine shop engineering buddy tomorrow

What did your machine shop engineering buddy say?

He thought that it might be possible - with a lot of problems that would have to be solved
The pressure spoken about here did not seem to scare him
I have not yet found out how much pressure you need to move cartridge case brass ( apart from the web and head ) a few thou mm ?
It might be in the realm of quite reasonable ?
The pressures generated by a normal discharge are what happens when the propellant ignites
To "form" the brass might not require anywhere near these sorts of pressures ?
A good engineer always designs a - well thought out pressure release / relief valve

Yea, I thought he was talking wildcatting stuff ? not just minor case forming.

Newton, when you shoot store bought ammo in your rifle, you mostly get good accuracy whilst at the same time you are fire-forming the brass cases. I developed loads in new cases and got excellent results. A small adjustment might be necessary on the use of the cases for the second firing. I therefore don't see any need for a special procedure to fire-form cases. My old 243 ammo shot wonderful groups after the rifle had been Ackley Improved.

My advice is thus to use normal reloading principles and shoot new cases in the discipline for which you need them.

If you are converting cases to a different calibre then such a procedure might be necessary.

Now you just need 30,000 psi to put in there...

All jokes aside. You basically you need to force in excess of 8 lt of air into a 4ml case.

Is it possible? Yes. But those of us with any sense know enough to want to be far away from the experiment.

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I was in a building once watching a bloke through some hanging like plastic sheets doing something around or on a hydraulic kind of thingee from a oil rig (I was working for BABCOCK at time) this guy suddenly like jerked and grabbed his chest and staggered off, I thought he had had a heart attack from where I was. I was later told that the thing they were testing had sprung a leak and it had basically shot him in the chest ? I answered that I had not seen any leak.
This was 40 years ago and I knew nothing of the subject at time and have always remembered that the guy I spoke to said the leak could have been like a hair thick and at "that "pressure" would just go through steel, brick whatever.The guy died because he had oil injected into his lung, or so I was told.
I know this pressure cutting to be true because at a later job we used a Hammelman V12 engine to run a high pressure water cutter to cut holes in buildings where dust was an issue. I also have a scar where I shot a hole in my finger when I met my first high pressure cleaning tool - Yip! I put my finger in front of it to see how strong it was :o quiet strong I very quickly found, still have the lightning bolt knuckle to knuckle scar.
So yea it could be a scary experiment.
I have not yet found a way of sealing the case as it changes form and caliber.

Now you just need 30,000 psi to put in there...

All jokes aside. You basically you need to force in excess of 8 lt of air into a 4ml case.

Is it possible? Yes. But those of us with any sense know enough to want to be far away from the experiment.