Pneumatic berdan deprimer

[Remiel]

has anyone made one? I have an idea using a bit of steel pluming and some wood and some air compressor fittings, either powered by a hand pump or small compressor, the plan is to build a frame to hold a 4in piece of mild steel pipe with caps on either end, one drilled and tapped for a male compressor hose fitting and dump valve the other will hold a relief valve, will have one or more holes drilled into the body and tapped for the rubber nipple end of one of the little blow or spay handles that come w/ air tools(cant remember the name) the frame will have a way to hold the brass of different sizes and something to catch the primers(so no one gets their eyes shot out). I wonder how much psi is needed to pop the primers w/o damage to anything else,

[Lars-K]

For safety's sake I believe using air is a bad idea. Also, the pressure needed is unknown, but I doubt it can be done with a "hobby" compressor.
I have used water and a piston with a o-ring fitted to the neck diameter. Works all the time, and it's totally safe.

[freebullet]

I tried it with a 200 gallon 220v shop compressor. It didn't work. If you have something better and it works let us know.

[Janoosh]

I have thought of using a compressor and a single stage press. A modified die to hold the shell, a shell holder, modified to allow passage of the spent primer. In the die is a rubber stopper and a valve. As the shell is brought up it engages the rubber stopper, pushing on the stopper opens a valve momentarily, and the pulse of air should pop the primer.
It's just an idea. Tried an unsupported case and air and it didn't work. I use Larry Gibson's idea in the stickies. Much easier and it works.
Good Luck with your endeavor.

[labradigger1]

I would think the brass would have to be in a sizing die to keep it from ballooning like fire forming. I would be cautious of the primers shooting out xfps (think air pellet rifle).
Lab

[Lars-K]

Here is a way of doing it with water:

http://www.dave-cushman.net/shot/hydraulic.html

[Remiel]

Here is a way of doing it with water:

http://www.dave-cushman.net/shot/hydraulic.html

welder yes lathe no, and no one to let me borrow one


I tried it with a 200 gallon 220v shop compressor. It didn't work. If you have something better and it works let us know.
was going to use a smaller(as in 3/8in or less) dump valve similar to the one used in cheater tanks to seat the bead in a big truck tires


I would think the brass would have to be in a sizing die to keep it from ballooning like fire forming. I would be cautious of the primers shooting out xfps (think air pellet rifle).
Lab
Idea was to have a catch box to prevent the flying primers but you may be on to something with the brass ballooning, without knowing the psi required it is possible. my friend and i are using Larry's method but are runnin into the issue of time and cause a lot of the cases we are doing this on are steel, the copper tube for the swages pockets, i found a place i can get berdan primers and my go that route but was looking for a dryer way of doing this that doesn't take 5+ min a case

[Garyshome]

The correct size drill bit a hammer and some water and a 2 x 4 with a hole drilled in it, It is a pita but it works, also soak the cases that have the sealer on them in some acetone for a little while.

[mdi]

The correct size drill bit a hammer and some water and a 2 x 4 with a hole drilled in it, It is a pita but it works, also soak the cases that have the sealer on them in some acetone for a little while. Yep, me too! I used a 19/64 drill for a "piston", filled the 7.72x39 case with water, placed the case over the hole in the 2x4, smacked the drill with a plastic mallet, primer out! I did it just for grins and may have tried re-priming some but did not where to get any Berdan primers...

[MtGun44]

Dangerous, I would guess. The pressure needed is pretty high and with
air it would be a reasonable approximation of an air gun. Need a non-compressible
fluid like water.

Bill

[44Vaquero]

Hydraulics' are the way to go! Yes. it's messy but very effective.

I will add one observation to this discussion: You would be hard pressed to deform any brass case using "Shop Air"!
Home Compressor's seldom generate over 200PSI. This is a small fraction of what a case is designed to handle supported or not!

[dudel]

You might want to consider what a blast of air is going to do to primer dust. That's nasty stuff. I would want to blast it into the air I'm breathing. Sort of like not using an air nozzle to blow off brake dust.

The water removal technique I saw was messy; but at least it kept spent primer dust out of the air.

[jmorris]

It will take a lot more than 200 psi and the pressure required to push the primer out won't damage the case or people would be blowing out the case when they are removing them hydraulicly.

Pressure is pressure.

[Remiel]

The correct size drill bit a hammer and some water and a 2 x 4 with a hole drilled in it, It is a pita but it works, also soak the cases that have the sealer on them in some acetone for a little while.
will give the acetone a try,


Yep, me too! I used a 19/64 drill for a "piston", filled the 7.72x39 case with water, placed the case over the hole in the 2x4, smacked the drill with a plastic mallet, primer out! I did it just for grins and may have tried re-priming some but did not where to get any Berdan primers...

http://www.lohmanarms.com/product_p/takv762nb.htm
Tula primers that i found web surfing, the only ones i have found

[376Steyr]

Home air compressors are generally limited to 125 PSI. Assuming the primer hole area is equal to a 1/8" diameter hole, I calculate a force on the primer of a whopping 1.5 pounds. I kind of doubt that will budge a normal primer. A crimped-in one would laugh at it.

[Remiel]

Home air compressors are generally limited to 125 PSI. Assuming the primer hole area is equal to a 1/8" diameter hole, I calculate a force on the primer of a whopping 1.5 pounds. I kind of doubt that will budge a normal primer. A crimped-in one would laugh at it.

Dad has one that goes up to 200+, but with all the post i think i will stay w/ hydro, as messy as it is

[country gent]

Rcbs made a tool that pried them out with a lever type tool after a hole was poked in it. At work we made a few Lee style decappers with 2 pins on the end at the same center line as the cases using drill blanks for pins ( the back end of a couple drills would work also) and a cup base you have to feel the pins into the flash holes but with the correct rod dia and practice this isnt a big deal. We would set them up in a vee block swing the rod in and then drill the holes with a small center drill and the drill size, then glue them in with a good epoxy making sure the pins were sitting on dead bottom of the rods holes ( this way the epoxy only had to hold them in place coming out). The water method works I have done them in that way. A grease gun might produce enough pressure to push primers out the trick is getting the sudden shock that the hammer driven punch has.

[freebullet]

I used an unregulated hose close to 225psi and high volume air flow. I used a deep well socket that the case fit snug in. Put that in a vice so the primer could shoot out the bottom unimpeded then placed body weight against the case mouth with a rubber tipped air blower nozzle. I hit the trigger & dumped full pressure on it. It didn't budge at all. This was tried on brass and steel cases of x39.

I've played with the water method in several ways. It works ok on brass but is less than desirable due to the ridiculous mess. It will rust case mouths on steel no matter what and is much less consistent than brass.

The best way I have found to deal with depriming steel (and brass) Berdan cases is to get a bolt that just fits in the case mouth freely. Cut the threads off, the remaining smooth shaft should be long enough for the head of the bolt to have a 1/2" to travel. That prevents the bolt head from hitting the case mouth. Then set the bolt straight in a deprimed case and use a fine tip pen or marker to mark the flash holes on the cut end of the bolt.

Harbor freight sells packs of multi sized itty-bitty drill bits. In one pack for 3$ you can make at least 4 of those bits into depriming punches. Use a center punch to mark the cut end of the bolt where you marked the flash holes. Only drill one hole and drill it slightly larger than the drill bits that fit through the flash hole. Then you can solder the mini drill bit in the cut bolt. You now have a non messy Berdan depriming punch that should be good for at least 5-600 cases.

I make a handful of those in 30 min and have punches made to do at least a few thousand rounds. With this method I sit in my living room and deprimed over a little cup with the case in a socket in my hand. Insert the punch twist a scootch till the drill bit drops in the flash hole give it a strike with a pair of pliers or mini hammer and the primer mess falls through the socket into the cup. I can do 600 in an evening easily with this method. Once you get going it's mindless you get in a rhythm and don't really have to pay close attention. I've posted pics on here before of the punches. Google "Berdan cast boolits" ya might find it.

I reprime with tula Berdan primers. I think grafs is where I'd ordered them. I made a small mod to the Hornady hand priming tool to feed the berdans. Repriming them is the exciting part, then your home free.

[jmorris]

225 psi is a lot for a normal air compressor even most 2 stage air compressors shut off closer to 175 psi, single stage in the 125 psi range.

If you want a high pressure compressor (or a vacuume pump) you can use a compressor out of an old refrigerator. Not much volume though.

[mdi]

Some answers are complex enough to give me a head ache :veryconfu.

K.I.S.S.; http://www.midwayusa.com/Product/245983/rcbs-berdan-decapping-tool

Homemade; http://theswissriflesdotcommessageboard.yuku.com/topic/2310/An-Uninteresting-Berdan-Decapping-Tool-but-cheap#.VKLZLdEsEM

If Berdan primers were more readily available or converting Berdan to Boxer was feasible, I'd look into it more. But all the cartridges I shoot I can easily find brass cases so I don't bother after the one time "I wonder if I could" experiment...

[fatelk]

I wondered about this years ago. A friend was given an old surplus industrial compressor from work, a 3 or 4 stage unit that put out something like 1500 psi as I recall he told me.

I thought it would be interesting (if I had access to a lathe) to make a device that would hold the case perfectly in a hole, with a small hole drilled for the primer to shoot out into a secure reservoir, a tube that would insert down in a case so the nozzle would be hard against the flash holes, and some kind of quick-release method to hold them together as it got a quick shot of air at 1500psi.

Of course I never got farther than just thinking about it, never even got over to get a look at the compressor. If I had some machine tools, lots of spare time, a bunch of berdan brass and a need to reload it, it might have been an interesting project. Then again there's the residual primer dust issue brought up in post #12. From an engineering perspective it's fun to think about but maybe not so practical. I guess I'll stick with water if I ever find it necessary to deprime berdan.

[Idz]

I used a tray of water with the case submerged sitting atop washer and a piston rod into the case mouth. A rap with a hammer dislodged even crimped primers and being submerged in water kept it spraying all over

[Reg]

Different things do different things when they are compressed. Pressure is always there but when water or oil is released it is quickly over with and the primer is easily controllable. Air on the other hand when released at high pressure tends to be like a delayed release the time depending on the orifice it goes through and the volume behind it. It would be easy to see the ejected primer going at very high velocity and if it got out of the trap it was in really doing some damage also you will have the time factor of releasing the high pressure air and then building it again for the next case.
Oil or water not only has to be much better to work with but also much safer.