After posting my initial results here I had a conversation with my neighbor JD and he shamed me into pursuing or should I say finishing what I had started. The hydraulic die concept was very intriguing and maybe more so to JD than me so I came back home and went to work with the ideas that we had brainstormed.
First off I needed a shell holder so looking around I found the first proto type Vickerman shell holder that was the candidate. I turned a plug to press fit the hole then counter bored it to .080 deep.
Next step was, to check the case protrusion from the bottom of the die, much the same way you would check headspace. This measurement was .071 so the shell holder was cut to .070, this in essence was headspace to give a .001 crush when the ram was camed over and bottomed out on the die base. The reason was (in theory) to seal the neck/shoulder junction before the hydraulic force was applied.
The next step was to expand all the necks of new Winchester brass with a K&M expander, then mic the ID of 5 cases which averaged .2235. From there a new piston would be fashioned with the neck area at .2245, just .001 over the neck ID. The thought was to seal everything better for the first stroke and in the end was the key to this process. The piston upper portion was fit with .001 clearances to allow for free movement; the step in this piston goes from neck area .2245 to .236 which is the bearing surface in the die, below is all the parts as finished.
Now with everything set up in the press, ram is cam’d over and bottomed out on the die, a case has been filled with water before inserted into the die, and the piston placed on top. At this time it would have been nice to have a dead blow hammer but I never purchased one so I used a block of wood between the surfaces. How much force did it require, not as much as one would think? I would say as much as driving a 1 ½ inch finish nail in a board so if you try this go slow at first and test the amount of force that it takes, you can always apply more. And now the mess, I was very surprised that there was almost no splatter, more from removing the case from the die than striking the piston. From this point the only improvements I can see is a hardened piston and a shell holder that has a grove for the case head to pull it from the die, other than that I think it is good to go.
Below are 5 formed cases, as I stated before it wouldn’t be worth the time to do this caliber but for the more difficult to form cases it would be a definite plus. As with everything on my site it is the way I see things and my opinion, it is my sincere hope that the readers come away with something positive or a different perspective on a new or old idea. If you should try this I hope that your results are successful.