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
I would want no part of pneumatic equipment operating at those sorts of pressures. There be whole flights of dragons in my chickenhearted opinion.
You need more than 20,000 psi for that. No, thank you.
Due to the uncompressable state of liquids, if something should rupture the pressure drops to zero pretty quickly without sending shrapnell everywhere. On the orther side, gas would heat up considerably under the pressure required and it tends to be very unhealthy being in close proximity to the event.
OK
You do realize that you are very close to something very similar ..
Every time you fire your rifle.
So make your die setup a very short clone of something similar to your rifle action and barrel
A die is in essence a rifles chamber
All one would need is one single valve operated "pop" of air - could even do it from a distance.
We are using compressed air which is a renewable resource rather than components which are consumables
Engineers work out these sorts of calculations all the time
Heavy equipment hydraulics work at these pressures all the time.
I will chat to my machine shop engineering buddy tomorrow
I can not see this being a problem or very dangerous if done properly. I do however see a tremendous amount of money being spent in making mounting and realizing the objective. This will not be a desktop item, more like a half ton workshop tool.
Would it be possible to change the form accurately in a cold form such as suggested?
Quote from: Newton on Apr 23, 2023, 04:19 PMOK
You do realize that you are very close to something very similar ..
Every time you fire your rifle.
So make your die setup a very short clone of something similar to your rifle action and barrel
A die is in essence a rifles chamber
All one would need is one single valve operated "pop" of air - could even do it from a distance.
We are using compressed air which is a renewable resource rather than components which are consumables
Engineers work out these sorts of calculations all the time
Heavy equipment hydraulics work at these pressures all the time.
I will chat to my machine shop engineering buddy tomorrow
There's likely much more difference between a rifle being used to fireform a case and a valve operated pneumatic system doing it with air than you suggest. Time being the one that leaps out at me. The entire operation is nano-seconds long in the rifle and I very much doubt that could be true in a pneumatic device and therefore the obturation that causes sealing to occur in a rifle chamber is not guaranteed to work the same. It may not work at all at practically achievable pressures and may require a different method of sealing.
I don't get your point about air being 'renewable'. Air just is. Unless you were generating the considerable amount of energy required for a contraption like this to operate from the sun or similar there'd be nothing more or less renewable about it.
Failures in hydraulic and pneumatic systems are barely comparable in their potential for destruction. There's a reason that compressor tanks are often tested with water pressure and it's not because its easier than doing it with air.
Google for some info on catastrophic failures of pneumatic system components for some eye opening viewing. The first such thing I experienced was a compressor that failed behind a nearby mechanics workshop. People reported hearing the bang from well over a kilometre away and two exterior walls of the structure were flattened. One of the guys in the shop was killed and the other was as good as deaf afterwards.
Quote from: Newton on Apr 23, 2023, 04:19 PM...
I will chat to my machine shop engineering buddy tomorrow
What did your machine shop engineering buddy say?
The stored potential energy in a pneumatic system is in a very very different league to a hydraulic system operating at the same pressure.
If a scuba tank fails hydro testing it does so with without much fuss, but if it fails while full of air, it takes a wall or a car or 2 with it.
I said previously I do not see this being a problem, I think I need to retract that statement. Last night while I waited for the night to pass I built this machine (I do these things in theory then approach the experts to find where I got the theory wrong), I started with a die set and ended up using a chamber and barrel basically - simple. Then things like keeping the pressure in the case and not just everywhere meant sealing the case mouth when it was in parent form and then keeping it sealed while it formed and moved, changed shape without the pressure going around sides of case and making a mess.
I went back to a die set and then made a die that would handle the pressure without blowing the case out bottom of die, I still have not found a way of sealing the neck of case to contain pressure while case forms.
I am now on back of mind all the time nearly 24 hrs, still have not built a system that will work even in dream world.
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.
Quote from: janfred on Apr 24, 2023, 08:22 PMNow 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.
*******************************
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.
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.
Yea, I thought he was talking wildcatting stuff ? not just minor case forming.
Quote from: janfred on Apr 24, 2023, 04:40 PMQuote from: Newton on Apr 23, 2023, 04:19 PM...
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
Quote from: Tripodmvr on Apr 26, 2023, 08:16 AMIf 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.
Quote from: Newton on Apr 28, 2023, 11:08 PMHe 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?
Quote from: oafpatroll on Apr 29, 2023, 12:56 PMWhat 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 !
Sounds like a solution looking for a problem and I still dont see any benefits to what you propose.
Quote from: oafpatroll on May 01, 2023, 11:17 AMSounds 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 -
Can be done at home, no.
Quote from: janfred on May 01, 2023, 06:47 PMCan 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 ...
Right. Please place the link...
Quote from: Newton on May 01, 2023, 08:35 PMQuote from: janfred on May 01, 2023, 06:47 PMCan 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.
Quote from: janfred on May 01, 2023, 09:57 PMRight. Please place the link...
Ultimate Reloader (https://www.youtube.com/@Ultimatereloader/featured)
Quote from: oafpatroll on May 02, 2023, 09:02 AMQuote from: Newton on May 01, 2023, 08:35 PMQuote from: janfred on May 01, 2023, 06:47 PMCan 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 ...
Quote from: Newton on May 02, 2023, 03:23 PMQuote from: janfred on May 01, 2023, 09:57 PMRight. Please place the link...
Ultimate Reloader (https://www.youtube.com/@Ultimatereloader/featured)
So, no pneumatic case forming? Not even in America?
How surprising...
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.
Quote from: Brian on May 02, 2023, 10:28 PMI 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!
Quote from: oafpatroll on May 03, 2023, 08:52 AMQuote from: Brian on May 02, 2023, 10:28 PMI 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. 😂😂
Happily none of my dreams were harmed by your post. A few of my nightmares may have been confirmed though ;)
Quote from: oafpatroll on May 03, 2023, 11:19 AMHappily none of my dreams were harmed by your post. A few of my nightmares may have been confirmed though ;)
Perhaps ?
https://youtu.be/a01QQZyl-_I?t=64
Quote from: Brian on May 02, 2023, 10:28 PMI 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 ....
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.
Quote from: Newton on Apr 22, 2023, 10:31 PMGreetings
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.
Quote from: 223 on May 07, 2023, 10:12 PMThe 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 ...
Quote from: janfred on May 07, 2023, 08:42 PMhttps://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 ?
Quote from: janfred on May 07, 2023, 08:42 PMhttps://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.ysterhout.net/docs/annealing/annealing2.htm)
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 ...
Please share with us your calculations or source