Ccrider
Gold $$ Contributor
I recently finished hydroforming a box of Dasher brass. My first time doing it. I split the necks on 2 cases out of the first twenty I did. Sort of worried me. After that, I did not split another case.
At the suggestion of @Dusty Stevens, I ordered a 5 pound dead blow hammer and used it for the last 50 or so cases. Wish I had bought it from the start. I got very consistent results with it using the same system. Fill the case, three strikes, refill the case two firm strikes.
I measured the shoulder on the hydroformed brass. If it was shorter than my average by more than .002, I refilled and hit it once or twice more. You get to where you can pretty much look at the brass and tell if it fully formed.
On my first strike, I got better results with a firm strike on the plunger while it was settling into the die and still had air in front of it. The air and alcohol seemed to form better than letting the plunger settle down to the alcohol and then striking. Your mileage may vary. All in all, not a hard task. Picture of the hammer:
At the suggestion of @Dusty Stevens, I ordered a 5 pound dead blow hammer and used it for the last 50 or so cases. Wish I had bought it from the start. I got very consistent results with it using the same system. Fill the case, three strikes, refill the case two firm strikes.
I measured the shoulder on the hydroformed brass. If it was shorter than my average by more than .002, I refilled and hit it once or twice more. You get to where you can pretty much look at the brass and tell if it fully formed.
On my first strike, I got better results with a firm strike on the plunger while it was settling into the die and still had air in front of it. The air and alcohol seemed to form better than letting the plunger settle down to the alcohol and then striking. Your mileage may vary. All in all, not a hard task. Picture of the hammer:
