Reloading GP11 / Berdan primed brass


December 29, 2012, 12:08 PM
First of all: no load data I could find published or even discussed in other forums mentioned using military brass and Tula primers. So I will not discuss load data here, just the process.

I don't know how to post pictures and so I didn't take any this time.

But, I figured out how to re-use the really nice GP11 7.5x55 brass. With household stuff.

I used a "high quality" 1/8" drill bit to barely pierce the primer cup, off center. No Harbor Freight bits, go buy you a pack of DeWalts. Don't go too deep, you'll hit the anvil - which is made into the case in a Berdan primed case.

Then, take a small nail (I think I used a 4d) and simply insert the point into the hole you made, and pry the primer out.

The GP11s were crimped in. If you drill your hole against one of the three crimps, then you are not prying directly against the other two and they'll slip out easily.

If you can stick the bit just right and stop it as soon as the cup is pierced, it'll pry it out too; but nails are cheaper than drill bits and I didn't want to chance breaking a bit.

I wore out two nails doing about 50 cases. I nicked a few anvils too; will see if those go off.

Graf's has Tula berdan primers and they fit just right in the GP11s.

I know, it's a lot of trouble to save a 45 cent piece of brass. And I've heard that water depriming works but I didn't have anything that would fit right in the case neck. Plus, it's cold and I didn't want to be slopping around in water in cold weather.

To resize, I used the Lee Collet die with the little aluminum cap milled out and the needle bearing pin pulled out; so that the mandrel could be there for the case neck to squeeze against but it wouldn't bottom out in the case.

Works good for me. YMMV.

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April 19, 2013, 04:33 PM
I finally started reloading Berdan Primed 7.5x55 brass. I always heard it was too hard to deprime and size so I never really took the time to think about it. It's not that much trouble. It just took a little time and a little thinking and a little looking.

To deprime you need to build a hydro - deprimer. Take a 6ft piece of 2x8 or 2x10. Cut three pieces two feet long. Nail or screw the two ends to the three foot piece making a bench.

Now Drill a hole a little larger then the size of the Cartridge you want to deprime about 1/3 way to 1/2 way through the top board..If you drill the hole too deep it will be hard to get the wet cartridge out of the hole. Now drill another hole all the way through in the middle of the hole you just made, just slightly larger than the primer. Place a 5 gal bucket underneath the "depriming bench" to collect the water and primers.

Take out the sizer from a lee or other inexpensive die..for my 7.5x55 that's a 308 which obviously works for several different size cases. Remove the pin. Dump the cartridges you want to deprime in a bowl, small bucket or container of water.

Take one cartridge out at a time completely filled with water and place in the hole that you have made that is slightly larger than the size of the cartridge. Place the sizer bar from a sizing die with pin removed, inside the edge of the cartridge case and hit with a hammer with moderate force. The primer pops out easily!! With a little practice you get very fast at this. Almost as fast as the standard method for boxer primers.

Dry the cartridges then check the flash hole for patency and uniformity. You can open the hole with a safety pin if it is not patent or uniform.

The primer is out the flash hole is examined and the cartridge is ready to size in the normal way except the pin must be removed from the sizing bar.

Trim to appropriate length and now your cartridges are ready for reloading.


April 19, 2013, 11:35 PM
How did you guys get rid of the three crimps?

April 20, 2013, 01:38 AM
For a commercial tool, the RCBS Berdan Decapper for $59.95 has been around for ages (at least since 1957 when I used one on 7.5x55 and 8x57 military ammo). Basically a pivoting hook to engage the case extraction groove, and an adjustable hardened spike to piece and lift the primer. It works on uncrimped primers like lightning: with crimped primers you might need to rotate the case to take a second dig and lift. For the three point stab crimp, I found a case neck chamfering tool would make short work of them, leaving a smooth edge.

There is a good discussion of other decapping tools on the message board.

No reason why the load data for Boxer primed brass would be much different with the GP11 brass, obviously starting at less than the maximum load!

April 20, 2013, 08:56 AM
RCBS has a swaging die that removes the crimps easily . I use that when it is needed.

April 20, 2013, 01:38 PM
Won't the built-in anvil get in the way of the swaging tool?

Matt Dillon
April 20, 2013, 11:52 PM
When I did a thousand or so of these a few years ago, I placed the cartridge into a socket of the appropriate size, and placed both into an old pie plate. using a bolt of the approximate diameter, I chucked it up in my drill press using a file and Emory cloth I brought it down to .308. After filling the gp11 brass with water, i used a hammer to whack the bolt to drive out the primer. This worked most of the time, but occasionally it would need more than 1 whack. After allowing the brass to dry out I poked a needle through each of the flash holes. This process left the primer pockets looking quite dirty, so I chucked up a brass brush in my Dremel and cleaned the pocket out. Next I resized the brass removing the decapping pin, and trimmed them to length in a Forster trimmer, chamfered it, and then primed it with my Lee Autoprime. Works great!

April 28, 2013, 02:20 AM
Maq, I've heard that hydraulic depriming is the way to go. I was even studying an arbor press at Harbor Freight yesterday, but figured that water and cheap chinese steel would be a rust factory. Didn't consider wood... gotta try that one out.

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