Hydraulic case forming

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.

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 will chat to my machine shop engineering buddy tomorrow

What did your machine shop engineering buddy say?

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

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.

Would it be possible to change the form accurately in a cold form such as suggested?

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.

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

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.

I would want no part of pneumatic equipment operating at those sorts of pressures. There be whole flights of dragons in my chickenhearted opinion.