Whack Dasher Cases into Shape with Hornady Hydro-Form Die

Fire-forming improved cases can be time-consuming and expensive. Now with just a mallet, a Hornady hydro-forming die kit, and a little H20, you can form Dasher and other improved cartridge cases easily and safely. And you won’t consume costly bullets, powder, and primers, or use up precious barrel life.

Three or Four Whacks Produces a 95%-Formed Case
With a Hornady hydro-forming die, water pressure does the job of blowing out the shoulders of your improved case. The process is relatively simple. Place a spent primer in the bottom of a new piece of brass. Fill the case with water, and then slip it into a special Hornady shell-holder with no hole in the middle. Then you run the case up into the forming die. Now comes the fun part. You gently insert a plunger (hydraulic ram) from the top, and give it three or four stiff whacks with a mallet (or better yet, a dead-blow hammer). Remove the plunger and you have a 95% formed case, ready to load.

Forum member Walter Queen (aka Queen_Stick) acquired a Hornady Hydraulic forming die kit through our Forum Classifieds. He used this to form 6mm Dasher cases. Walter tested to see how many mallet blows would be required to form his dasher cases. Using a regular mallet, four or five blows was the magic number (with a Dead-blow hammer, one can often do the job with three strong whacks). Shown below are test cases with 1, 2, 3, 4, 5 and 10 (X) mallet strikes. Walter explained: “It helps to use a consistent yet aggressive swing with the mallet. I did a little test to show what’s happening to the case with each swing. The numbers on the cases refer to the number of swings with the mallet. The last case, with the ‘X’ on it, I actually hit it 10 times. The extra effort made no difference; anything beyond 5 swings is likely a waste of time!”

What’s the “happy face” case with the split shoulder? Well, as a test, Walter tried one older, work-hardened piece of brass. This split its shoulder on the third strike. Walter concluded: “You MUST have new brass, or freshly annealed brass. The ‘smiley case’ shows a split neck. For that case, on the third swing of the mallet the piston slammed down into the die and bottomed out [and] the water shot out of the split in the neck.”

Read More on RiflemansJournal.com
You can learn more about the hydro-forming process in a detailed article on German Salazar’s Rifleman’s Journal website. There, you’ll find more photos, and Walter provides helpful tips on how to hydro-form cases most efficiently (and with the least spilled H20). One tip is to “fill the cases with a syringe of some sort.”

Hornady supplies a shell holder made specifically for the hydro die; there’s no hole in the bottom of it. Just insert a spent primer into the primer pocket and you’re ready to go. The spent primer combined with the solid shell holder, keeps the water from seeping out of the primer pocket. The primer pushes out a little bit during this process, but it’s impossible for it to come out because of the way the shell holder is designed. The shell holder has a grove which allows the case to slide out of the shell holder even when the primer protrudes a bit.

How to Order Hydro-Forming Die Kits
Hydro-forming die kits, which include forming die, plunger, and special shell-holder can be ordered through the Hornady Custom Shop. Hornady can create a forming die kit for most popular cartridges, if you provide a die print or some full-formed sample cases. To order, contact Ben Syring at Hornady: 800-338-3220 (ext. 261) or bsyring [at] hornady.com. If you have an oddball wildcat, send Ben the specs for your chamber and three (3) pieces of fire-formed brass.