DIY, glorious Berdan (and Boxer too) deprimer … yes, there are pics.

[Boris]

Unless you are just being released from GULAG re-education program, you know that Berdan primers are available and plentiful. So how are you de-capping all the brass that you have been collecting and saving for this day… ?

Comrades endlessly bitch about how inconvenient it is to deal with Berdan, well … since your mom stopped wiping your ass, life has been getting more and more inconvenient, so STFU and get back into the bread line!

There are several advantages to decap hydraulically:

1. You don’t care if brass is Berdan or Boxer primed, which means you don’t need to stare into each cartridge and count holes, being afraid to break the decapping pin. Once your brass is decapped, it’s easy to see if it’s Berdan or Boxer.
2. You don’t need to sort anything, , caliber, whatever … just drop the cartridge and get the cap off
3. Much faster than RCBS “chicken claw” tool.

Here is an example of what RCBS claw works, it’s pretty damn slow. It is good for lazy capitalists:

[video=youtube_share;pKqwaGmZEW4]http://youtu.be/pKqwaGmZEW4[/video]


This Aussie is using “wet crotch” technique which is probably the fastest and fool proof teqnique, however, there are a few things that he left out:

[video=youtube_share;FskNx4UBZvc]http://youtu.be/FskNx4UBZvc[/video]


The basic idea is a tube, one end is capped with a hole, large enough to pass primer through. Fill with water, insert plunger, hit with hammer. Water is non-compressable, so hitting the plunger is like hitting the primer directly (at least in theory) In reality, some water will be blown between the plunger and pipe, there is air pocket in the primer, some force of the blow will be dissipated.

I found a description to make a hydraulic tool similar to what crazy Aussie was using. Here it is assembled. May be I’m missing something, but this tool is total crap, it would never work and I hope that Trotskist who posted that is get caught and end up chopping timber in Siberia.

To improve on things, I took 6” of 3/8” black pipe and ½ rod which is available at any home stores. The black pipe contains a weld joint inside. It needs to be removed with a 1/2 “ drill bit. The end was capped/drilled, you can’t really see that from the picture. As plunger I am using about 3-3.5” piece of the rod.

This setup can get some primers out, but it works about 25% of the time and you really need to hit the plunger with vengeance.

After many drinks of vodka and two tapes of Tchaikovsky, I started to wander why the pipes in Australia are so friggin’ thick. Perhaps wet-crotch was trying to hide some information? My best guess was that initial shock of the blow of the hammer was dissipated by the weak, AR looking setup. I needed a much heavier tube/pipe.

I took my existing 3/8 “ pipe, put it into a piece of electrical counduit and poured lead in the middle. I came up with this contraption:

Now the “device” worked really well. It fits most cartridge from 30-06 to other AR, girly and pistol cartridge. A few of cartridge are Boxer primed, some are steel and some were varnished. They all decapped at the first blow.

This was all good, but cartridge of Mosin Nagant does not fit into ½ hole. I had to make a special tool. Get ½ “ EMT conduit. That runs for $2 for 10’. Grab a 5/8” x 5” bolt, that should set you back another 2 rubles. The cap was made from a bit of steel. It had to be turned on a lathe to make sure that surface is perfectly square, otherwise you are going to drip water.

Eye-ball how much EMT you need and cut it.

Cartridge of Mosin is large and has a real primer, wide and big. It needs no special heavy tool like puny AR cartridge. You will be able to generate enough hydraulic pressure to pop them on a first hit.

After you fill the tube with water, drop the plunger in. It will start to sink. Once it is sunk half way, hit it! If you hit too early, you may damage the tube. The primer holes are nice and clean too.

The water is not very messy. Try putting scalps of hippies around your anvil to soak up water. Happy shooting comrades!

 

[wahsben]

Spasiba comrade.

 

[EddieCoyle]

Cool. Mine is a bolt through a round piece of plywood, a bucket, a 9/16 socket, a dowel and a mallet.

 

[drewh14]

Good info Boris! As always, your posts are hilarious!

 

[BradM]

A+ post!

 

[Boris]

Cool. Mine is a bolt through a round piece of plywood, a bucket, a 9/16 socket, a dowel and a mallet.

you said it was corian. Can you take pictures of your setup? I found your post after making all this stuff, I don't know what's easier. I believe that you hammer yours upside down with plunger going into the cartridge. Does it need to be a tight fit? How reliable is it in terms of getting the primer out on a first blow, does it ever damage the cartridge?

For this setup, I was thinking about setting the tool in a shallow pan of water so that there is no need to make it 100% water tight at the bottom, or refill it between the decaps.

 

[EddieCoyle]

you said it was corian.

I took the Corian for something else. The bucket too. I'll look around later today to see if I can find the rest of it. I haven't used it for a while so I'm not sure if I hung onto it. It was never intended as anything more than a temporary setup

The piece of plywood is/was round and sized to fit tight in the bottom of the bucket (to keep it from floating up - that's why Corian works better). The bolt wasn't a particularly tight fit in the neck. I used a long 1/4-20 bolt with the threads cut off (like yours) and counterbored the wood base so the bolt head would fit flush. I also ground the cut end of the bolt so that it was rounded.

To use it, I filled the bucket up about half way with water, and placed a bunch of cases mouth-up in the bottom of the bucket. I duct taped a socket (I think it was a 12-point deep 9/16" or 14mm) onto the end of a piece of 3/4" dowel about 16" long. Keeping everything under water, place one of the cases base-first into the socket, start the case mouth onto the upside down bolt, then smack the other end of the dowel with the mallet. Once you got the technique down, it worked every time.

 

[Warm_Garand]

Nicely done, Boris.

The virtue of the Aussie wet crotch method is that you are not generating pressure INTO an unsupported case--the brass experiences no pressure at all--except at the web (thickest part of the brass) and then only at the just-larger-than-the-primer sized hole (path of least possible resistance).

Now, as I see it the next obstacle to be overcome is to channel and divert the spray of water with a sluice-gate and rag.

Nice to see it happening, Boris.

 

[Slowdive]

....I started to wander why the pipes in Australia are so friggin’ thick. Perhaps wet-crotch was trying to hide some information?

In the comments section of that video, he details his BOM:

You would probably be better off going to a second hand steel merchant. 8" of 1" diameter brass and 4-5" of 1" stainless round bar. A drill slightly bigger than the primer. The ability to bore out the brass bar and lastly the ability to silver solder. You can get away without the need to silver solder if you can use a bottom drill (flat end) to get the nice flat base inside the hollow bar.

Looks like he is routing out a solid piece of cylindrical brass stock on a lathe or press and just drilling a hole in the bottom. I might try that. Unfortunately I threw most of my Berdan brass out.

 

[Slowdive]

Now, as I see it the next obstacle to be overcome is to channel and divert the spray of water with a sluice-gate and rag. Nice to see it happening, Boris.

I was thinking of something like this. If fitted properly there would be very little spraying and the water (& primers) just get recycled into the bucket.

 

[Boris]

In the comments section of that video, he details his BOM ...

comments, instructions ... I never read those

I don't think that going with a brass pipe is a good idea. It's crazy expensive, brass is like $2 / #. Then why??? 3/8 black pipe is under $2 or even less. Same effect. The only issue is you have to weight it down (the lead around part), unless you get really good with hammer. My Mosin decapper, it's not weighted down, but then Mosi's caps are nice and wide and easy to get out.

 

[Boris]

I don't get even remotely the same amount of spray that the Aussie guy has in his video. In the Mosin decapper photo, there is that piece of rubber that I put under the decapper to stop any water leaking.

This setup with a hole collecting water under the cap, the issue is that cartridge don't make a completely watertight seal with the flat bottom of the drum, so water will run out. Aussie dude placed his setup on a wet block of wood that seals the bottom. I used a bit of rubber or wood.

Another idea I was thinking about is may be putting the whole setup into a small bucket of water, so that only piston sticks out. Any splashes should be pacified and contained. I haven't tried that yet. Soon ...

I was thinking of something like this. If fitted properly there would be very little spraying and the water (& primers) just get recycled into the bucket.

 

[Slowdive]

This setup with a hole collecting water under the cap, the issue is that cartridge don't make a completely watertight seal with the flat bottom of the drum, so water will run out. Aussie dude placed his setup on a wet block of wood that seals the bottom. I used a bit of rubber or wood.

What if you put your thumb over the hole on top after you dip it in the water? That should prevent too much leaking out until you are ready to place the piston (like a straw full of water). Admittedly, having never done this before, I'm strictly working off theory.

 

[Boris]

What if you put your thumb over the hole on top after you dip it in the water? That should prevent too much leaking out until you are ready to place the piston (like a straw full of water). Admittedly, having never done this before, I'm strictly working off theory.

not a bad idea, I wasn't dipping it in a bucket like the Aussie dude, but pouring from a cup and that made far more mess. I think that going through a thousand cartridges would definitely id the best technique.

 

[Warm_Garand]

Some sort of a check valve--passive restriction limiting water loss to a passive trickle--but as soon as it got hit with the overpressure from a hammer-strike the flow would just pass/jet through.

..or how about a rubber o-ring laying on the bottom, inside the ram chamber/tube? Overpressure would force the brass case-head against the rubber, sealing it--but still allow the water to explode through the primer pocket.

Also--and not to get too convoluted--the dipping/filling of the tube occupies about 1/3 of the time and motion of the process--what if you had a small pump (like on tile cutters, aquariums, etc.) sending a gentle stream of water into the recess where you set the tube, so it filled automatically? Not a huge volume of water--but just enough to fill the pipe while you are occupied with setting the next cartridge case in the mouth, retrieving your ram, and your hammer.

Just some ideas, to get things percolating.

PS> Slowdive, that is kewl schematic/visualization software--what is it, where can I get some, is it hard to use?

 

[richc]

Andrei you are a mad genius!!!

 

[Slowdive]

Some sort of a check valve--passive restriction limiting water loss to a passive trickle--but as soon as it got hit with the overpressure from a hammer-strike the flow would just pass/jet through.

..or how about a rubber o-ring laying on the bottom, inside the ram chamber/tube? Overpressure would force the brass case-head against the rubber, sealing it--but still allow the water to explode through the primer pocket.

If you built a dedicated table, you could just put a trap under the plate and attach the hose to the end of it. Most traps have a plug you can unscrew which is where most of the primers would collect. I think if you set an oring in the base plate, that'd work well to control up-spray.

PS> Slowdive, that is kewl schematic/visualization software--what is it, where can I get some, is it hard to use?

LOL, your going to be disappointed but that is just the drawing tool on MS Powerpoint. It's not ideal, but I've done enough .ppt preso's so that it didn't take me too long. I have a PC at home that has Visio on it and I would have used that, but I only had my laptop at the time so I had to make due with what was loaded on that...which was MS Office.

 

[Warm_Garand]

Boris:

I got my prototype up and working. I decapped about 80 rounds of MAS today, just for proof of concept.

I posted some pics and a synopsis here:

http://www.ar15.com/forums/t_6_42/362609_Hydraulic_Decapper_for_Berdan__Home_Built_.html

Using the bronze sleeve and flange, I find that the unit actually holds water perfectly until you set the ram into the neck (!).

My pedestal is lame--but hey, it beats a stump (lol).

All the best.

--Warm_Garand

 

[Boris]

Boris:

I got my prototype up and working. I decapped about 80 rounds of MAS today, just for proof of concept.

I posted some pics and a synopsis here:

http://www.ar15.com/forums/t_6_42/362609_Hydraulic_Decapper_for_Berdan__Home_Built_.html

Using the bronze sleeve and flange, I find that the unit actually holds water perfectly until you set the ram into the neck (!).

My pedestal is lame--but hey, it beats a stump (lol).

All the best.

--Warm_Garand

that looks excellent!!! ... and no machining required!

 

[Warm_Garand]

You need a hacksaw to cut the square end off the end plug--and you do need to enlarge the hole of the endplug so the bushing which supports the case head seats--but like I said it is watertight (except for minor drips) so you don't have to hurry setting the ram.

VIDEO: