can you make priming compound?

[Texantothecore]

TTTC, I believe that the U.S. Army switched from H-48 (which contained ground glass) to FH-42 (which did not contain ground glass) because they determined that the antimony sulfide crystals could serve as grit.

In this excerpt (page 54) from the 1922 book, Microscopy of Small Arms Primers, the author includes the specifications for those particle sizes -


https://books.google.com/books?id=oh...rimers&f=false

I definitely am going to test a batch without the ground glass. The percussion nipples (treso) have much larger anvil and striker surfaces and I suspect that it might work with the antimony sulfide. The volume of powder being crushed and shifted is much greater than with a firing pin and it is good to know that in at least one formulation the glass was found to be redundant.

Thanks for the info and the link.

[therealhitman]

Nice lab work! Impressed am I.

[Oreo]

Indeed. I especially like that a good non-corrosive primer can be made without ground glass. Just the idea of sending ground glass down the bore is like nails on chalkboard to me.

[perotter]

I spent a little time again looking for and finally found the heat of formation for lead nitrate. If I can find or at least estimate the heat of formation for Pb(H2PO2)2, it won't take long, a few hours, to figure out how much oxidizer is needed. My experience has been that when I've optimized that the primers are both more reliable and sensitive.

@Marshall
Are you using a gum or shellac? It would be interesting to see if there is any noticeable difference if you aren't.


FWIW. While looking for that I came across something that is highly interesting in the area making primer compounds that I should have time to test in the next few days. If it looks like it has potential use, I'll post about it.

[perotter]

@ Marshall

I know I read a patent that when used other nitrates in addition to lead nitrate that worked. I think they are Remington ones. If I remember right, both double salts and triple salts are formed and how much of each directly dependent on the % of each nitrate used. As I'm now curious about it, I'll spend a little time looking for it.

PS
Was just looking and was reading Brun's patents. He states in 2239547 there that for lead styphnate primers "requires the addition of a small quantity of a substance which is more sensitive to percussion, such as tetrazene (guanylnitrosamilroguanyltetrazene), leadnitrato-hypophosphite, and the like."

Then 8052813 used just 20% tetrazene so maybe a 20% leadnitrato-hypophosphite would work. In the French patent it was 20% tetrazene, 48% barium nitrate, 8% Al, 24% antimony sulfide.

Maybe a primer with 20% leadnitrato-hypophosphite and the equivalent in lead nitrate to the 48% barium nitrate would work. That's about all I have time for today and don't even have time to figure the % of weight for the lead nitrate to provide that same oxygen as the 48% barium nitrate.

[Desertbuck]

Wow! I can't believe how far this thread has come since it was started. Lots of good hard to come by information. And interesting ideas, keep them coming guys keep up the good work. Wish I had more to contribute but I have just been so satisfied with the Frankford Arsenal mix that I haven't pursued another. And truth be told primers are coming back so i haven't made any in awhile.

[perotter]

Wow! I can't believe how far this thread has come since it was started. Lots of good hard to come by information. And interesting ideas, keep them coming guys keep up the good work. Wish I had more to contribute but I have just been so satisfied with the Frankford Arsenal mix that I haven't pursued another. And truth be told primers are coming back so i haven't made any in awhile.

Since 2009 I also have been satisfied with the FA mix and have firearms of all types that won't rust when using it. For me after that it is a more a hobby thing.

[perotter]

@All,

More testing data:

EP Mod 14 50% initiator, 25% oxidizer, 25% fuel (no glass)

Pb(H2PO2)2 25%
Ba(NO3)2 50%
Sb2S3 15%
CaSi2 10%

100%

This does NOT work. I could tell when seating the anvil, that no double salt formation was taking place. The cup only contained a moist goo that easily squished around. So, this is a dead end. On-the-other-hand, the lack of reaction between Ba(NO3)2 and Pb(H2PO2)2 gave me hope that using Ba(NO3)2 in the place of PbO2 would work.

EP Mod 13 50% initiator, 25% oxidizer, 25% fuel (no glass)

Pb(H2PO2)2 25%
Pb(NO3)2 25%
Ba(NO3)2 25%
Sb2S3 15%
CaSi2 10%

100%

This mixture works about the same as EP 9 which it was based on. I encountered one primer that would not fire and discovered a potential problem in my build method. It appears that the packed pellet sometimes does not completely moisten which limits how much reaction takes place. This was proven by scrapping out the unfired mixture for the failed primer, moistening the mixture outside the cup and repacking the moist mixture into the cup (with the dimple removed). After drying, the primer fired normally. I have probably been having this issue all along with all of my test primers. Therefore, I may have to go to wet packing until my tests are completed.

@perotter,

At the moment, I am not using any binder. I have been able to get away with this because the double salt reaction itself hardens and binds the pellet together as the lead nitratohypophosphite crystals form. As this happens during and after the anvil is seated, the resulting hardened pellet makes for a very reliable primer. That is partly why I prefer dry loading and then moistening the packed pellet. I have found that if you delay seating the anvil too long after moistening the mixture, it becomes difficult to seat them because of how hard the pellet becomes. Because of this, in my latest build method, I only moisten 5 primers at a time so I can quickly seat the anvils before the mixture becomes too hard.

Regarding finding/calculating the optimal amount of oxidizer/fuel. I think I have enough guidance from published information on this topic. Experimentation will allow me to hone in on the best ratios to use. However, please share anything you find or calculate on this question.

Marshall

The advantage of using software to calculate to how the different amounts of oxidizer/fuel effect the compound is that in a few minutes one knows the both the amount of hot gas produced and temperature of it for a number of different percentages.

After an initial run of using different percentages of what one thinks would work, one can quickly see the ranges that show the best potential. Then run again with much finer percentages(think 0.25% or less) to optimize the mix.

By spending an hour or less with a computer and analyzing the output one can compare the experimental mix's amount and temperature of gases to known production mixes. But, even then there still needs to be enough make it and try it experimentation to occupy any time have available.

Everyone should use the methods that make the them the happiest when working on a project of this nature.

[Texantothecore]

Marshall, did EP Mod 10 work?

[TheDoctor]

Anyone looked into Al-Bi2O3 yet?

[TheDoctor]

Can't get the link I want to copy. Google "Bi2O3 for priming". First link should be a pdf from dtic.mil. There are numerous references I'm looking at, but my research is in its infancy. I just got keyed onto the aluminum bismuth trioxide idea yesterday. Apparantly the NSWG has been doing a lot of research into this, and it seems that this will be the compound of the future.

[TheDoctor]

Ok, slam on the brakes for the Al-Bi2O3 idea. Further research reveals a fatal flaw to my plan. It seems that it's not just the addition of the aluminum, but the particle SIZE that's critical. Currently, and possibly forever, beyond my ability to make, and not economically feasible to purchase grades that fine. Talking nanometer scale....

[perotter]

Ok, slam on the brakes for the Al-Bi2O3 idea. Further research reveals a fatal flaw to my plan. It seems that it's not just the addition of the aluminum, but the particle SIZE that's critical. Currently, and possibly forever, beyond my ability to make, and not economically feasible to purchase grades that fine. Talking nanometer scale....

A the nanometer size Teflon and aluminum work as primer compounds, but 4-5 years ago nano sized aluminum was over $160 a gram. Cheap enough to try, but too expensive for consider as a DIY primer.

[perotter]

After drying the primers in a food dehydrator for about 30 minutes they were tested as usual in a 380 ACP case. The primers fired, but were very weak. Disassembling the fired primers showed about twice the normal residue compared to previous successful primer formulas. I have concluded that 20% initiator is too low to get reliable ignition. It may be possible that replacing some or all of the aluminum with CaSi2 might help. In any case, I consider this formula a failure.

So far, I like EP mods 9 and 13 the best.

Marshall

New information: I tried EP Mod 15 which is the same as EP Mod 12 except the Al was replaced with CaSi2. After drying I got the same result, only a weak pop and lots of residue left in the primer cup after firing. So, it doesn't seem possible to make a 20% initiator formula work.

Did you try a 20% mix with lead nitrate or lead dioxide instead of barium nitrate? But, I'm good with a 30-40% mix.

Also, I'm thinking of use lead nitratohypophosphite as a sensitizer if a couple of simple non-corrosive mixes I made that didn't fire very often. I can't try them until after l get the fall getting ready for winter tasks done.

[Safeshot]

Cabela's has Large Rifle, Small Rifle & Small Pistol Primers "in stock" for $24.99 per 1000. Buy one of each, store in an ammo can, should "get you through" any period of "shortage" or "non supply". Purchase more when they are "on sale" and when Cabela's offers "free shipping". Just one approach.

[perotter]

Cabela's has Large Rifle, Small Rifle & Small Pistol Primers "in stock" for $24.99 per 1000. Buy one of each, store in an ammo can, should "get you through" any period of "shortage" or "non supply". Purchase more when they are "on sale" and when Cabela's offers "free shipping". Just one approach.

For a couple of decades I've kept a minimum of enough inputs to make at least 30,000 corrosive primers. Costs for the salt substitute at the nearest grocery store and the sulfur from the local garden store was about $4.00.

That last time I had to relied on DIY primers was decades ago when I was in college and the roll caps I used allowed me to practice shooting, period. Also the free powder used from book matches helped greatly.

[perotter]

FWIW.

Some guanine nitrate arrived today that I'll be using to make both primer compound(two different ones) and for making powder.

While there is no needed at this point to make a non-corrosive mix other than what Marshall is making, guanine nitrate can be made from easier to obtain(locally around here) chemicals if the need occurred.

Also, I doubt the primer compounds will be as safe to use as his method. I won't be doing much work on either of these until the snow flies.

[Oreo]

Mind saying who? Or where to buy said punch?

[perotter]

FWIW.

The only reason for the paper that is in a primer cup is to keep primer compound from sticking to the punch that is used when wet loading. If one is dry loading, there is no need for the paper.

Also if you are setting up to reload primers, you really should make matched primer plates. For wet loading make one set that indexes over the cup plate. Between these 2 place a properly sized piece of paper. Then you when press down the punch it will both cut the paper and put it into the cup.

[perotter]

One of the pro's of tetrazene is that what is needed to make it can be made easier than the ones for lead nitratohypophosphite. Of course at this point it this isn't a major concern, but who knows what the future holds.

Thanks again Marshall for sharing your important work in this area.

FWIW. Now that Marshal has shown how to make 2 different primers that are good for long term storage, I'm going to go back try a couple that are useful as short term use. The only advantage being the ease of getting what is needed to make them. I'll be starting the first on this week end, as I have Saturday night free and have the base chemicals, etc here.