Over time I have found the need to decap Berdan primed cases and I've found the usually recommended hydraulic method messy and somewhat in effective. I'm not certain where I came across this method, but over the years it has worked well for me on the occasions I've need to use it. First the usual warnings - reloading ammunition is an inherently dangerous hobby that require the utmost attention to detail. First and foremost do not attempt to use this method to decap live primers. If you choose to follow this Instructable you assume all responsibility for the results.
You will need the full length resizing die for the case you are working with, your loading press (not pictured), case lube, a scratch awl, a small hammer and the cases you wish to decap.
Step 1: Set Up the Die in Your Press
Remove the decapping stem from you die. Now screw the die into the press from the underside so that the die in even or just a little above the top of the press. Depending on you die/press combination you may have to remove the lock ring from the die. In my case with the Rock Chucker press and the Lee 7.62x54R die it wasn't necessary to remove the ring.
Step 2: Drop a Case Into the Die
Pretty much that simple. Lightly lube the case and drop it into the die. I usually press down lightly so the case does wiggle in the die.
Step 3: Decap
This is the step that I found impossible to get a decent picture of (not enough hands) Place the point of the awl against one side of the firing pin indent in the primer and give it a couple of sharp hits with a small hammer. You want the awl to penetrate the cap without damaging the wall of the primer pocket or the internal anvil in the primer pocket. Now pry the primer up and out of the pocket. The picture shows a freshly decapped case.
Remove the case from the die and repeat as necessary for the remaining cases. The picture shows a primed case, a fired case and a decapped case.
Step 5: A Few Final Thoughts
Berdan primers come in a variety of sizes, most of which don't fit the priming arms on tools meant for Boxer primers. There are a number of internet sources for primers and priming tools. Each individual will have to determine if dealing with Berdan primers is worth the time and expense. In some instances it may be the only was to have ammunition for that old but serviceable rifle or handgun. There are also some commercial Berdan decappers that all seem to be rather pricey. We just the few cases that I've wanted to do I've not been able to justify the expense, however were it necessary to do a lot of cases the tool would be a necessity I would think.