Better way to hydroform?

[bdevr]

I have a few hundred 7.62 brass floating around and wanted to try hydroforming. My only issue is with the hammering the dies while in my press. Has anyone ever tried making a secondary press that would mount to the top of your reloading press to forcefully "press" a 6.5mm punch into the case full of water creating the pressure needed to expand it?

Does my hair brained idea make sense?

[StoneTower]

Unless you had some type of air operated or motor driven ram that moved quickly, the punch would not seal the water in the brass. Get an old cheap Rockchucker press off craigslist and have at it.

There is a lot of force generated by the shock of a hammer. I have press parts together with an arbor press and had a 30 ton press maxed out. A small rap from a hammer that weighs less than a pound causes everything to go into place. It is really cool the first time you see the parts slam together.