Making Sparkplugs: My first 100 primers

[P Flados]

Caution ------------ Warning ------------- Danger

Take extra care to make sure reloaded primers are fully seated in the case prior to assembling your ammo.

Today I assembled 50 LPP and installed them in my modified 38 Sp cases.

After the initial 3 hr bake at 120 degf, I brought them into the house. I was looking at one an noted that the primer was just proud of the case base. I went through the batch and found another 6 with the primer sticking up a little. I took the 7 cases into the garage and ran them back through my Lee hand priming tool to get them all at least flush. I applied pressure very slowly and carefully, but still had 1 of the 7 go off.

Some guns are capable of pushing a proud primer further into the case when chambering a round. Unless we can figure out how to stop getting these EPH 2x primers going off when being seated in a case, making sure all primers are seated at least flush before loading the case is more important than ever. If you do not get these primers at least flush, these guns would be at risk for having the gun fire as a round is being chambered.

[Castloader]

I hadn’t thought of that, but I have been giving the priming process some extra care. I always prime with my hornady handheld priming tool. I can feel when the primer is right and if I pop one, as long as it’s pointed in a safe direction, we’re good. Lately due to inconsistent anvil height, I’ve been running my finger over each primer to make sure it’s seated flush or slightly deeper before I move on. Good observation.

[P Flados]

My last couple of batches have been assembled in a 1/8" plate with holes. I think I am getting 5% to 10% more powder in the cups and it is taking me longer between wetting and putting the primer in the case. I think this is making it a little harder to get primers flush. I think I need to adjust my anvil seating punch/die to reduce assembled primer height by 0.003" or so.

[dverna]

There is a lot of value in this thread. Someday we may be forced to produce primers and this will be critical information. The other value....when primers drop to $40/k, only a fool, or the poor, will not stock up.

Interesting thread.

[Castloader]

Yes, in spite of all I’ve learned, stocking up is still far better. Being self-sufficient is great, as is continuing to shoot when many cannot, but it’s nowhere near as good as having a stockpile of components to last a lifetime.

Makes me wonder if some future guru will start a thread on how to make smokeless powder…

[Castloader]

My last couple of batches have been assembled in a 1/8" plate with holes. I think I am getting 5% to 10% more powder in the cups and it is taking me longer between wetting and putting the primer in the case. I think this is making it a little harder to get primers flush. I think I need to adjust my anvil seating punch/die to reduce assembled primer height by 0.003" or so.

Interesting. That could also account for the primer seating AD’s you’ve had more than I. I’ve had one in 400 so far.

Do you think any of the primers mentioned earlier had somehow backed out of their cases? Did you wet prime the cases and then dry the primers? I’m wondering if the anvils could move while drying.

[P Flados]

My initial problem was installing primers into cases after letting the primer mix dry. Once activated (wetted and then allowed to dry), my mix was going off when slowly being compressed during seating.

Because of this problem, I started seating the primers in cases before just after wetting.

[Castloader]

Ok. Yes, I think your cups are overfilled. I always dry my primers before priming cases and I don’t have this issue. (Except once, and who knows what happened that time). What is your primer AD rate?

[ofitg]

I've dabbled in primer remaking with "Prime-All". That's the old military H48 corrosive stuff (but they won't tell you that). First thing I learned was their method of "a scoop of this and 2 scoops of that" just doesn't work. You need to weigh out the components per Aardvark Reloading. I got much better results that way, but still not 100% "bang". So I put in a punch cut roll cap (for toy guns) in the bottom of each cup, added the compound, packed it down with a bamboo skewer, a drop of denatured alcohol with shellac added, a punch cut paper cover on top and seated the anvil. I also added a touch of aluminum powder and baking soda to the compound.

Oldsalt, your method sounds similar to what I tried last year. I placed a paper cap “dot” in the bottom of the cup, and wet it by misting it (a few sprays from an atomizer bottle) with common 70% isopropyl rubbing alcohol. I topped off the cup with a mixture of potassium chlorate (60%), antimony sulfide (30%), and confectioners sugar (10%). Next, I wet the top surface of the mixture with rubbing alcohol again and then seated the anvil. The sugar acts as a combustible binder, and baking soda was not needed because there is no sulfur present.
I allowed the primers to dry for a few days (a small desk fan helps) before seating them in cartridge cases for testing. Over a period of several days I tested 100 of these primers and every one popped.

I have been making my own potassium chlorate, but antimony sulfide is a bit more difficult to get. Lately I dabbled with an idea presented by “Wicket” in this old post, substituting homemade tin sulfide for antimony sulfide -

https://castboolits.gunloads.com/sho...14#post2752814

My set-up was fairly simple – I mixed 15 grains of powdered tin (from Walmart) with 10 grains of sulfur and dumped the mixture into a titanium “crucible” (actually, a titanium shot glass). I heated the bottom of the cup with a propane torch -



I should mention that this torch (from Amazon) seems to be more powerful than the old propane torch I bought from Ace Hardware years ago. Within a few seconds I could see smoke coming out of the cup, and a few seconds later I could see flames coming out of the cup. It only lasted a few seconds, then the flame and smoke stopped. I looked down into the cup, and the titanium bottom was glowing orange-red. I shut off the torch and allowed everything to cool down.
I recovered 19 grains of dark crumbly solids from the cup – this corresponds nicely to 15 grains of tin bonding with 4 grains of sulfur. Evidently the excess sulfur just burned away, up in smoke. As I was pulverizing this material with a mortar & pestle, I could see tiny sparkles of reflected light scattered across the surface – apparently this material has a basic crystalline structure. I mixed up some H48 compound, substituting this material for antimony sulfide on an “equal weight” basis, and loaded a few percussion caps. After they dried, the percussion caps performed perfectly.

One of these days, I intend to try powdered pewter (more than 90% tin) instead of pure powdered tin.


Technical note - when the tin/sulfur mixture reaches 900 degrees C (1650 degrees F), it ignites and the chemical reaction occurs, producing tin sulfide.

[P Flados]

What is your primer AD rate?

Over 5% for sure, possibly closer to 10%.

[Castloader]

There’s always the possibility that there’s something off with your lead hypo. Although I would expect problems elsewhere, not priming cases. I would start with lowering your anvil height, and then see what happens.

I’m thinking about the batch size. I follow the recipe straight out of Marshall Thompson’s pdf and that charges 100 SPP cups. If you’re doing the same, then you can’t really be overfilling the cups as long as the powder is equally distributed.

[Castloader]

@ofitg, thanks for that, I’m sure the guys working through the H-48 method will be delighted. Chemistry can be fun when things go right. Personally I hated it in high school, but the experiments were so dull it’s no wonder. When my son is in chemistry class he’ll probably enjoy it more…

[Castloader]

I think I may have made a batch of magnum SPP's today.

I was making a second batch of EPH25 and using the 100 mesh NC from my coffee grinder. It's wonderful not to have to grind with the mortar & pestle for a half hour or so just to make 100 primers. Anyway, I had a batch of EPH25 already made up, sitting in a small container ready to divide into the cups. I dropped 100 cups into my primer loading plate and sprinkled the mixture over the top as I had before. To my consternation the mixture did not fill all the cups. During previous sessions, I'd have to scrape and spread the mixture many times to help convince it to fill up the cups. This time, I spread it all over, and there was plenty of room left. Several cups were nearly empty, and others at various stages of filling. At first, I figured some of the cups must be overfilled, so I gently teased the powder out and kicked it around, but it was obvious that the cups were still low.

I did some quick math and made up a quarter batch, stirred it up and spread it around. This time it really did fill the cups up. Unsurprisingly, when tamping, it seemed to me that the cups were now somewhat more full of mixture than in the past. I finished wetting, placing the paper wad, anvil and set them. A bunch of anvils were hard to set and kept wanting to come out. I decided then to prime the cases while the mixture was wet, anticipating some AD's if I waited for it to dry. Seating the primers I noticed that many did not want to seat the last couple thou or so and needed some real encouragement to get to the happy flush/slightly below flush seating point.

The only difference between this batch and the previous ones, was that I ground the entire EPH25 mixture in my mortar & pestle after mixing. Normally, I just mixed the Lead Nitrate, Lead Hypo, Pyrex and NC together with a glass rod for a few seconds, then spread it over the cups. I think the LN got ground up very finely this time. The LN comes out of the bottle like fine play sand, and previously gave a very gritty feel to the mixture. This time, it was like spreading talcum powder. I'll have some more experimentation to do here. I also noticed that the wetting process was more like EPH 20 this time instead of my previous batch of EPH 25 where the mix seemed to slightly resist wetting.

I'm considering doing a test like one on Rumble where different mixtures are fired in empty cases in a dark room with a pistol and a ruler to show relative flash levels. I'm really wondering how these primers stack up with flash level compared to commercial primers.

I am trying a new case drying technique since the cases are wet primed. I put a 1" thick spacer grating on the bottom of my Instant Pot, put a circle of cardboard on top, and placed my primed cases on top of that, sitting in their ammo trays. Now, if somehow I had a detonation during drying, the blast would not affect any of the adjacent primers. I have it set to 130 degrees for 12 hours. I do not anticipate any issues with having cardboard in the Instant Pot, I can already hear folks recommending against that due to flammability concerns. I'll probably use something else eventually, but I wanted a buffer to keep the primers off the bottom of the pot where the surface temperature is higher.

NITROCELLULOSE
In order to speed up the process of making future batches, I wanted to make a bunch of 100 mesh NC. I threw about a quarter cupful of Power Pistol in the coffee grinder yesterday. Every so often, I'd grind it for 60 seconds then move on with my day and let the bearings cool down. I did this perhaps 5-8 times between yesterday and today. This evening, I finally dumped it all onto my 100mesh screen and sifted. I got about 90 more grains of fine Nitrocellulose. Added to what I had before, I now have enough to make about 2,400 primers. This step eliminates the biggest PITA of making a batch of primers. The NC really resists grinding, but using a larger volume helps it grind much more effectively. For anyone already making primers or thinking of getting into it, a cheap coffee grinder dedicated for chemicals is proving to be extremely valuable. If I want to make more ground Pyrex, you can bet I'll be recruiting this little guy.

[P Flados]

My hand coffee grinder came in today. I tossed in about 200 gr of Promo (bulk Red Dot, a fast flake) and hand ground till 90% was through the grinder, dumped the outlet bottle back into the inlet and repeated again and again. Every so often I would toss the outlet bottle contents over into my sifter set. The results was around 70% of 60 - 80 mesh, 10% of 80-100 mesh, and 20% less than 100 mesh with much of that being almost dust. With the really fast flake, I am hoping this is fine enough.

I measured up a mix of 11.7 LN, 11.7 LH, 4 GG, 6 NC, 1.7 AL. Over at MeWe there was some discussion of going down on the ground glass (GG) to allow more NC and/or AL.

I assembled 20 primers with this mix for testing. I seated anvils (punch/die now set for 0.119" instead of my previous 0.125"). I did not insert the primers into cases. I want see what they do for both UD (Unintentional Discharge) and for power.

I also assembled 10 similar rounds using my older batch of NC and a more standard mix for comparison.

Neither batch went to the oven yet. I will probably give them an hour at 120 degf just before inserting them into cases.

For power level testing, I am firing primed 38Sp out of my 8" TC Contender with the muzzle firm against a cardboard box. So far, my most powerful LPPs rupture the first layer of material and leave a pretty good burn. Good SPPs scorch the cardboard. Weak primers leave a little residue and no real scorching.

[Castloader]

I just tested 2 primers from last night's EPH25 batch. I set up my iPhone on Slo-Mo to try to capture the flame in a dark room. Results were very good. Peak flame length was more than 12" from the muzzle of my Glock19.

[P Flados]

Impressive. Plenty of flame and lots of streaks from your AL.

I did initial testing of the two batches discussed in my last post. All 20 went in with no UD. I could not tell the difference between them as far as power.

These were much easier to get seated "at least flush". I think most of my primer reloads that went off during seating were ones that required very high thumb pressure to get the handle to the position that is typically "good enough" for full insertion.

I assembled 100 more for testing to see if I want to go back to drying before insertion.

I also assembled 5 made from a mix with NC under 100 mesh and normal ratios to see if I can tell a difference in power from my under 60 mesh NC.

[Castloader]

Yes, it seems the fine AL particle size did not cause any problems. I need to do an EPH20 comparison at some point. I think I'll be sticking with EPH25 though for general use. Too easy to upgrade from EPH20 and no downsides provided I have lots of AL powder which I do.

I've also finally joined the Mewe group, so you might see me over there as well.

[Castloader]

I also assembled 5 made from a mix with NC under 100 mesh and normal ratios to see if I can tell a difference in power from my under 60 mesh NC.

I’ll be interested to see those results

[mvintx]

NITROCELLULOSE
In order to speed up the process of making future batches, I wanted to make a bunch of 100 mesh NC. I threw about a quarter cupful of Power Pistol in the coffee grinder yesterday. Every so often, I'd grind it for 60 seconds then move on with my day and let the bearings cool down. I did this perhaps 5-8 times between yesterday and today. This evening, I finally dumped it all onto my 100mesh screen and sifted. I got about 90 more grains of fine Nitrocellulose. Added to what I had before, I now have enough to make about 2,400 primers. This step eliminates the biggest PITA of making a batch of primers. The NC really resists grinding, but using a larger volume helps it grind much more effectively. For anyone already making primers or thinking of getting into it, a cheap coffee grinder dedicated for chemicals is proving to be extremely valuable. If I want to make more ground Pyrex, you can bet I'll be recruiting this little guy.

Well that does it for me. I'm gettin' an electric coffee grinder. Got lots of Power Pistol too. It's my 'go to' powder for 9mm and .40.

[P Flados]

I ran the evening tests. I have had only had one UD out of 125 while seating EPH 2X primers in cases. I have a habit of putting pretty firm pressure on the primer after it gets all the way in. For the one that went off, I am sure I pushed harder than needed.

For power level testing, the under 100 mesh NC was definitely better than the under 60 mesh.

The under 60 mesh might be good enough, but I decided that I would do what it takes to go at least one mesh smaller.

I went and "re-processed" my container of under 60 mesh. My hand grinder is much more efficient at reducing NC to under 60 mesh than it is to getting under 80 mesh. It took quite a bit of work to get 50% reduced to below 80 mesh.

Looking at it, I am pretty confident that the bulk of the cheap ceramic burr hand coffee grinders are all about the same. It is better than anything else I tried, but it leaves lots of room for improvement. These things really are meant for coffee beans. We really could use more precision and finer tooth spacing on the burr.