6mm BR to .30BR Robinett

HINTS ON USE OF OUR HYDROFORM DIES

Basic Steps:
Fill the case full to the top with water or light oil and hit the drive pin 3 or 4 times. You can hit it more but if the first few hits are strong enough, the case will already be fully formed, and the extra hits do not achieve anything. Go by the look of the case when it comes out of the die. We use water as it works well and is easier to clean up. Some dies, such as the 6BR to 30Br die, work best if you fill only to the bottom of the case neck, but the 6mmPPC and 6mm Dasher work best with a full case. A few trial cases will quickly show you the best results.

More Detail:
Use an old ice cream container or similar and add a few drops of dish washing detergent to about 50mm of water as this breaks down the meniscus (resistance to flow) of the water and lets the case fill easily. I use a dead fall hammer which is a special type of hammer with something in the head that stops it rebounding when you hit something. This stops the drive pin bouncing back and flying up in the air. However, a normal steel hammer around 2 lb or 1 kg will do a good job also, but the pin will fly back out or the case due to the hydraulic pressure generated in the case by the hitting action and will crash down on the floor, maybe damaging the pin. You can lay a piece of material over the pin when you use a steel hammer and that will catch the rebound, or have some mats around the work area to soften the fall of the drive pin. Try and always hit the pin square on in the middle as it may break if hit repeatedly on the side of the head.

I always use the die in a bench mounted vice, as I find it works better if the die is on a solid mounting, and I would never use the die in my reloading press as bashing a good press with a hammer just does not seem very smart to me.

Unlike some hydroform dies in the marketplace, our AbD dies are designed to expand the neck inside diameter when necessary and to seal on the neck so that maximum hydraulic force is generated inside the case and hydroforming fluid is not leaked to the outside of the case inside the die as that will prevent the case from expanding to the required shape and dimensions.

You can damage the drive pin if you are careless when hitting it, resulting in off centre forces being applied to the pin. We have purposely designed the pin with a larger diameter up under the head to try and prevent bending and breaking the pin as they are hardened to prevent scoring and damage to the pin shank where it expands the case neck. The pins are also highly polished to once again prevent damage inside the case neck and give a smooth finish on the brass case. If you do damage your drive pin, we can supply replacements. Please contact us. If you have any further questions or suggestions on hydroforming cases, please contact us.

PS. Do your calculations, but we believe you will pay for your hydroform die in the first 100 or so cases that you form.

Happy hydroforming!