Pistol Primers as Cores

[AzoMittle]

Alright, so I got a question or six for all the reloaders out there.

 

In the Best of AFN II there is a short article on Silver Flitter, in it the author mentions they use large pistol primers as star cores to create a crossette like effect, shattering the star into several pieces.

 

 

Crossetting flitter stars are easy to make using pistol primers as cores. It is first necessary to waterproof the pistol primers by spraying with a can of flat aluminum spray paint. After drying, several hundred primers are rolled in a pan, alternately misted with a 50/50 alcohol/water solventand dusted with increments of composition #2 until the desired size is reached. These stars will break with a crack into several fragments, producing an attractive crossette-like effect.

 

-DB

Googling it I see there are different hardnesses (Federal, CCI, Winchester)and types (Regular, Magnum, Winchester). Along with the fundamental difference of Berdan vs Boxer.

 

1) What causes the primer cores to actually ignite as a star core: is it direct flame via the flash holes or conductive heating as the surrounding unburned comp warms up? Or something else entirely?

2) How safe is it to be rolling these? Would a harder primer be safer? They will be banging around, against each other, against the walls of the container it is rolled in, and I'm figuring inevitably a few will be dropped on the ground.

3) Would the difference in type make any change besides how hard of a break it would create?

4) Any reason the Berdan vs Boxer difference would matter?

5) The author states the primers were "waterproofed" using "flat aluminum spray paint". This doesn't make sense unless the flash holes are somehow plugged. If left unplugged it would be like spray painting with a stencil, you couldn't completely cover the comp.

6) Knowing what's generally in the non-corrosive and lead-free primers are there any special precautions or chemical incompatibilities?

 

Composition #2 (just for reference for the curious)

40....KP

60....Al (-325 Mesh Bright Flake)

05....Dextrin

[Eyegasm]

Primers in general are of the fulminate or azide family. VERY, VERY shock sensitive and extremely energetic. Extremely dangerous stuff. I'm not sure how safe a primer would be in an aerial shell or anything else subjected to a lifting charge or bursting charge. I would guess the risk of a flower port or worse would be pretty high. Azides are especially sensitive. For me the risk of a detonation would be too great to risk it.

[AzoMittle]

Primers in general are of the fulminate or azide family. VERY, VERY shock sensitive and extremely energetic. Extremely dangerous stuff. I'm not sure how safe a primer would be in an aerial shell or anything else subjected to a lifting charge or bursting charge. I would guess the risk of a flower port or worse would be pretty high. Azides are especially sensitive. For me the risk of a detonation would be too great to risk it.

 

I was thinking the same thing, I was a bit taken aback when I read it.

 

BTW, unless I get the go-ahead from a mod I was trying to avoid mentioning the comp, I didn't want to get the post shut down.

 

 

I saw the two families you mentioned on another site as being used but only historically, not in the present. I'm familiar with the latter (hence my username) and know of a few places it is still used currently but not in pistol primers (not to say it isn't). I saw this on a gun forum,

 

"Fulminate of mercury destroys the brass cartridge case (embrittles it). The last fulminate primers were a hundred years ago or so. They were replaced with potassium chlorate primers (so called "corrosive" primers). The chlorate primers were very good, but they left a salt in the barrel that would attract moisture and promote corrosion - thus the need to clean after using with special solvents or hot water.

 

Chlorate primers were replaced by [redacted] primers (non-corrosive primers) that are still in use."

Edited March 6, 2016 by AzoMittle

[Eyegasm]

After I posted the brisance factor rang in my head too. The shock wave would possible destroy the stars in an aerial shell as well. Maybe not in an extremely small amount, but then again it's probably just easier to use BP or even 1 gram of a good flash comp or some whistle. My background is more in the HE and reloading world personally. Kind of why I have been more interested in the creativity and artistry of Pyro in recent years. More fun and less chemistry. But even in my HE days I stayed far away from fulminates and azides. Too dangerous.

[Eyegasm]

I have read about cheddite primers coming into Vogue. I can't speak from experience on them, but they are supposed to be pretty good and just as reliable. However I think we are in the wrong thread for the topic. I would be real interested in the results from any trials or experiments you or anyone else has done. New things are always interesting.

[schroedinger]

Maybe you should shoot a pm over to rogermayw, he had made a video where he shows them.

[DavidF]

I actually load the primers into crossettes with whistle and use them to break the crossettes. I am not aware of any other person that has tried this. It is probably due to the incorrect assumptions that the primers will somehow go off while protected from heat and shock inside a star or crossette. The Japanese use red explosive inside stars, which is far more sensitive than a pistol primer is. How often do primers go off when handling bullets? I have done this several times now and never had a problem. Here is my first shell made this way. There are others on my channel, and also a short clip of the loading method I use.

https://www.youtube.com/watch?v=2i_kmSBXOxk

[Eyegasm]

That is very interesting. Inside a crosette. How have the breaks been with regard to stars? Do many go blind or would you say the results are generally as good as BP? When I think about it, with the smaller size of a primer compared with BP, that may enable more crosette per shell volume or more stars or glitter. Now you've got me wondering. I had never considered it just based on the shock sensitivity, but if it works consistently it may open the door to some very interesting creations. Have the primers ever caused a flower pot? And if they did, what were the effects on the launch tube?

[DavidF]

Eyegasm, I don't understand this: "How have the breaks been with regard to stars? Do many go blind or would you say the results are generally as good as BP?"

 

I have never had a flowerpot (with primers). Keep in mind, the chemicals used in primers may be quite sensitive by themselves, but that doesn't mean the primer is as sensitive. They are manufactured to rigid specifications. Primers have carefully dosed amounts of active ingredients, packaged in such a way as to make them safe to handle. Sure, I have only done a few shells this way. If you look on the internet to find crossette shells with tighter timing using traditional methods, I can think of only 2 examples. 1 example was only with 5 crossettes, and the timing was super tight (Lloyd's). My shell above had 47. TR's are in a class all their own, so they don't count

 

Due to the time it takes to make a good crossette shell, if I ever had a flowerpot I would seriously reconsider my methods. Keep in mind crossettes are routinely filled with sensitive compositions like chlorate/antimony, 50/50. Just to be clear, I'm not talking about making regular stars act like crossettes. I'm talking about making crossettes act like crossettes. Either way, If fire does not get into a shell prematurely, I can't see how a pistol primer would go off early, whether it's in a crossette or inside a rolled star.

[rogeryermaw]

I did roll a few blue stars on primer cores and though I didn't use them in a shell, they did work as intended from a star gun. They seemed quite able to withstand handling and manipulation without popping at the least provocation. As has been said above, primers have to be able to take some minor amount of abuse. Otherwise they'd be useless in combat and hunting situations.

[AzoMittle]

Eyegasm: I'm willing to try them and post results as long as the general consensus is that it is safe to roll with them. I won't be able to post results until the club shoot in September though.

 

Rogerymaw: Any chance you remember which primers you used? I have a feeling most would work but the more details you can share the better.

 

As I've been thinking about this I had two new ideas:

 

1) These would probably work for cut stars too! While the comp is damp, a primer could be pushed into it and later pasted over or married with another star.

 

2) A similar effect could probably be achieved by filling something like gel capsules (like used for vitamins and pills) with loose flash powder; the problem with using gel capsules is they would dissolve, almost need ones made from HDPE, PET, or similar. Similarly, you could probably roll comp onto some sort of core that has a different solvent than the comp, poke a hole into the star while it is still wet, dissolve the core and back fill it with flash through the hole, then paste the hole over with comp.

[Eyegasm]

With the stars going blind I was wondering about the effect (if any) on the physical matrix of the stars. After reading my post again I see how I wrote that wrong. Somehow I forgot we were discussing crosettes. Yesterday was a day from hell at work and I was probably too tired to be posting. Sorry.

[Exo]

I have made 3", 4" & 5.5" ball and can shells using large pistol and rifle primers as star cores, I sealed the primer flash holes with very thick n/c lacquer to stop any water contaminating the primer cores. I used stars that were rolled with the primer cores and also cut stars that had the primers pushed into the comp. most of the stars burned completely before the primers exploded but there were some that had remains of the unburnt star shooting off after the report, but not much.

The primers just explode when they get hot enough from the star comp burning, I have used them with glitter comps. and a red comp. its a nice effect.

Just as a safety measure when rolling the stars I only rolled batches of 50 primers at once.

[rogeryermaw]

Sorry I couldn't give an exact part number but they were Winchester small pistol primers in a small white circle metal can.

 

Similar to this:

Edited March 10, 2016 by rogeryermaw

[Eyegasm]

From reading the input it seems as if the idea is really a feasible one. Very interesting. The next time I have project time I might look into this. Primers would be an amazing way to save space and weight.

[Mumbles]

Save space and weight versus what?

[Eyegasm]

The potential energy of primer is greater per weight and volume than BP or Pyro compounds in general. I meant it as that milligram for milligram there is more energy in primer.

[otto]

Sorry I couldn't give an exact part number but they were Winchester small pistol primers in a small white circle metal can.

 

Similar to this:k2-_af54d3f0-075b-43aa-bf6f-60943f5a9e84.v1.jpg

Just a point of identification: that is not a primer rather a "percussion cap" intended for black powder ignition. I don't know what the composition is in them (wiki says mercury fulminate) but since they are not as picky to handle I'll guess it is different. Actual primers can be contaminated by the oils on your fingers and rendered inert by that. The caps are not susceptible to that and are usually packaged in bulk.

 

Primers generally come packaged like this:

 

[Fulmen]

Actual primers can be contaminated by the oils on your fingers and rendered inert by that

Bah, I've handled thousands of primers with my fingers without any problems.

[otto]

Bah, I've handled thousands of primers with my fingers without any problems.

Just relating the usual reloading advice on them. Maybe it's from days gone by where excessively (gun) oily hands were the norm for loading types. That said I'm still careful to not. Despite that, I've had 2 primer related FtF in 30 years of reloading. My buddy had 5 factory rounds in one box that wouldn't pop so I guess I'm doing OK.

[rogeryermaw]

Just a point of identification: that is not a primer rather a "percussion cap" intended for black powder ignition. I don't know what the composition is in them (wiki says mercury fulminate) but since they are not as picky to handle I'll guess it is different. Actual primers can be contaminated by the oils on your fingers and rendered inert by that. The caps are not susceptible to that and are usually packaged in bulk.

 

To be fair those were not the exact item I used. Just an illustration. The primers I had, I'm fairly certain, were lead styphnate. It was a red powder compound and capable of initiating etn with about .3gm

 

So as not to cross into h.e. territory, that's all I'll say about that. But ya that image was just to illustrate the packaging my product came in.

[Eyegasm]

I have heard about that too with primers and the oils from fingers. I have never had any problems, but my experience with primers is just in self loading. I usually handle azide primers with latex gloves anyways. A lot of people with expensive degrees claim it could be very carcinogenic because supposedly aides can be converted by human biology into cyanides. Besides latex gloves are that expensive. I never really bought into the argument myself, but the gloves don't hurt.

[Fulmen]

Excessive amounts of oil can cause misfire, but it takes more than normally clean fingers to cause it.

 

As for primer compounds, according to VihtaVuori's 95' reloading manual the most common initiaters are lead tricinate and tetracene, common oxidizers are barium and strontium nitrate as well as lead and manganese dioxide. Fuels are calcium cilicide, antimony nitrisulfide and aluminum.

[Eyegasm]

Interesting. I was under the impression they were all either fulminante or azide. I've been out of reloading for a while. Thanks for the info. I think it's time to get back into it. If it wasn't for all the permits and regulations here. Soon enough though.

[dusty56]

In his book Round Stars and Shells, David Brown talks about using small pistol caps as cores for stars to produce a "Crackle" effect. I believe he said the primers could be rolled with a clay coat to make them easier to roll. He did not mention a brand/part number but since the primer is going to cook off from the star heat it should not be a problem.