Homemade percussion caps

I am working on developing a process for making homemade percussion caps that can be gathered from items commonly available in a home shop. This could be a cheap alternative to the Tap-o-Cap style of formers, which appear to work very well, but have a relatively high initial cost, especially if you need two of them to create different sizes of caps.

So far, the results are promising. Aluminum sheet for the caps is easy to come by, and I have thicknesses of .035" and .025" to work with, aluminum roasting pan and Red Bull can, respectively. 1/2" and 7/16" punches seem to be in the ballpark for creating appropriate sized caps. From a #12 wood screw with the head cut off I created a handled mandrel that is used to form the cap. From various washers I have created shaping and sizing dies for the caps. I use some scrap wood for anvils to hold the washers, and to drill holes into for rough forming the caps.

The biggest difficulties are centering the mandrel on the disk for shaping, and forcing the disk to pass evenly through the shaping and sizing holes. The disks tend to get slightly (or a lot) off center, and the cups end up with uneven edges. Another issue is creating evenly distributed folds around the disk so that the cap forms evenly over the end of the mandrel. My goal is to create a die sculpted into the head of a bolt that can be hammered onto a disk to both dimple it for the mandrel tip and crease the disk to make folds. I ground one that does the creasing but not the dimpling, so for now I'm just rubbing the disks on top of crease lines filed into washers.

The current caps aren't precisely what I want, but I'm pretty close.

Attached are pictures of the process, and an Xcel file with measurements of finished caps.

More pictures

Have not seen a Tap-O-Cap since the 90s.

This is the current thing, and it works way better than the old Tap-O-Cap.

https://22lrreloader.com/

A great big sincere thank you, salute and a handshake for your time and posting this

Johnny Tremain said:

Have not seen a Tap-O-Cap since the 90s.

This is the current thing, and it works way better than the old Tap-O-Cap.

https://22lrreloader.com/

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Yes, I have just ordered some Prime-all from them, but I don't know if they have a specific name for their cap making device, other than "cap maker."

There is an extremely good white paper about percussion caps by "Mako" at https://guntoters.com/blog/wp-content/uploads/2018/10/Percussion-Caps-and-Nipples2.pdf It is very helpful in understanding their form and construction.

Very ingenious how you set up all the pieces to make caps, but for me, the time spent doing all of this is not worth it. I bought the cap maker and it's easy to use, quick, and looks like it does a more consistent job. Kudos to you for trying to create a better mousetrap...

The mail order quick and easy do it yourself tools almost defeats the point of do-it-yourself.

It's nice to know how to be able to build things from scratch if you're far from home and need to put things together that you need.

Reading about an fella, that during the civil war the federals came by and seized his firearms and ammunition,

He had a family to take care of , needed a firearm for defense as well as fetctin meat, so he went several miles out into the woods and built from scratch a forge and actually made a rifle and a handgun, he made his own gunpowder too,

I found an interesting thing at the thrift store today. It's a device for setting plastic snaps in fabric. The shape of the mechanism reminded me of the old Ideal reloading tools. It's a press with a plastic plunger that presses down on an anvil. If you remove the plastic plunger tip, the shaft of the plunger is about .015" in diameter, that is about the right size for forming the interior of a percussion cap (they seem to come out slightly larger than the diameter of whatever tool I have used to form them.)

By fiddling with things, I managed to press one nicely shaped cap with an interior diameter of 0.161", which is the interior diameter of a #10 percussion cap ( I don't remember which brand ATM.) But I messed up about 7 aluminum disks in the process, and it was not a repeatable success.

The big problem lies in forming the disk into a cup shape. Trying to force a flat disk through a round die usually results in a punctured disk. I can manually shape the disk into a conical shape with radial ridges around it, and then work that through successively smaller dies (finish washers and flat washers), but that is really fiddly. And keeping the disk centered on whatever I'm using to shape it is fiddly, although the finish washers make that easier.

The disk needs to be passed through some conical die, the bottom of which becomes a short tube that makes the cap shape as the aluminum blank passes through.

This little hand press, if it could be suitably adapted to the purpose would be a useful tool, but it is migrating away from the idea of improvising a cap maker from stuff that people commonly have in a modest home workshop.

I got my Prime-All order today. I have been working with the cap making project of an evening, here and there. I bought some brass shim stock from Ace Hardware. I bought a multi-pack, containing small sheets .005", .003", .002", and .001" thick. My micrometer measures them as .0045", .0025", .0015" and .0005" thick. My micrometer is digital, and only measures to .0005", which I assume is its level of accuracy, so the sheets are probably closer to what they are supposed to be. The .005" stock is definitely too thick to use, and the .001" stock is too thin. I have tried the .003" stock, and it works nicely. I haven't tried the .002" stock yet. The brass is harder to cut than the aluminum, no surprise.

I have also ordered three nipples that fit my CVA guns. I have been using a #10 wood screw shaft as a pushrod, but I had the idea that using the actual size nipple my guns have as the former for the cap might make more sense. I will probably have to grind off a lot of the nipple below the cone so that it will fit down into my die without rubbing the sides, which is why I ordered nipples instead of using the ones already in my guns.

So...lots of tinkering to do.

CEvonk said:

I got my Prime-All order today. I have been working with the cap making project of an evening, here and there. I bought some brass shim stock from Ace Hardware. I bought a multi-pack, containing small sheets .005", .003", .002", and .001" thick. My micrometer measures them as .0045", .0025", .0015" and .0005" thick. My micrometer is digital, and only measures to .0005", which I assume is its level of accuracy, so the sheets are probably closer to what they are supposed to be. The .005" stock is definitely too thick to use, and the .001" stock is too thin. I have tried the .003" stock, and it works nicely. I haven't tried the .002" stock yet. The brass is harder to cut than the aluminum, no surprise.

I have also ordered three nipples that fit my CVA guns. I have been using a #10 wood screw shaft as a pushrod, but I had the idea that using the actual size nipple my guns have as the former for the cap might make more sense. I will probably have to grind off a lot of the nipple below the cone so that it will fit down into my die without rubbing the sides, which is why I ordered nipples instead of using the ones already in my guns.

So...lots of tinkering to do.

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Shouldn't be an issue for you because I have seen how meticulous you are (meant as a compliment). Just remember to clean asap, especially after firing caps made from the Prime All. They are MUCH more corrosive than regular primers and will can initiate rust within a few hours in some conditions. I'm in the south with high humidity, which I'm sure contributes a lot.

CEvonk said:

I got my Prime-All order today. I have been working with the cap making project of an evening, here and there. I bought some brass shim stock from Ace Hardware. I bought a multi-pack, containing small sheets .005", .003", .002", and .001" thick. My micrometer measures them as .0045", .0025", .0015" and .0005" thick. My micrometer is digital, and only measures to .0005", which I assume is its level of accuracy, so the sheets are probably closer to what they are supposed to be. The .005" stock is definitely too thick to use, and the .001" stock is too thin. I have tried the .003" stock, and it works nicely. I haven't tried the .002" stock yet. The brass is harder to cut than the aluminum, no surprise.

I have also ordered three nipples that fit my CVA guns. I have been using a #10 wood screw shaft as a pushrod, but I had the idea that using the actual size nipple my guns have as the former for the cap might make more sense. I will probably have to grind off a lot of the nipple below the cone so that it will fit down into my die without rubbing the sides, which is why I ordered nipples instead of using the ones already in my guns.

So...lots of tinkering to do.

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BUMMER! I bought some .005 sheets a few months ago! Let us know the better of the 2 and 3.

So, I fooled around some with the Snap Pliers, which is what the device pictured in a previous post is called. It actually works very well. It as these kind of firm but squeezable 3/8" diameter rubberish tubes that the rod goes through. In normal operation, you the plunger and the rubber part operate to press the pieces of a snap together so that it is mounted on a piece of fabric. But if you withdraw the plunger from the rubber, and use it as a die by centering a 7/16" diameter brass blank between it and the plunger, the plunger will push the blank down through the rubber tube and form a very nice cup shape. That's cool, if you have one of these devices, or could build one.

But I also happened on something at the hardware store (because I was looking for things that could be used for this purpose.) It's a 3/8" diameter nylon spacer for #8 screws. I think it cost 40 cents. It has an inner diameter of 0.174", IIRC. Using the plunger that I made from a dowel and a #8 wood screw with the head cut off and filed down to .153", I can press a brass blank through the spacer and make a very nice cup. Since the spacer is 3/8" in diameter, and the brass blanks are 7/16" diameter, it is very easy to center the blank on the spacer.

I tried using aluminum with this method, but the aluminum is too soft, and is pierced every time. The brass is a tougher metal, and folds very nicely into a cup shape. I have used both the .002" and .003" brass to make cups, and they both work well. There is practically no noticeable difference it the effort required to form cups from the different sized stock. I also tried .005" stock, but it is too thick, and won't go through the nylon spacer. Instead, the plunger just pierces it the same way it pierces the aluminum blanks. I did chamfer the hole in the nylon spacer slightly, and I think that is a useful modification of the spacer.

I made videos of the process, but the files are very large, and not extremely informative.

Here is a picture of cups produced by the manual plunger and nylon spacer. If I can get the sizing correct, I think this is a very good technique to use. The brass is definitely harder to cut into blanks. My hollow punch is made from whatever pot-metal Harbor Freight had on hand, and while I have sharpened it, it doesn't cut extremely well. The aluminum material is no problem to cut, but the brass takes more...finesse.

Also, I tried doubling up on the aluminum, but that just makes really clunky, badly folded cups.

Just a few thoughts...

1. How long will tue nylon last?
2. Could a spacer of mild steel or aluminum work better?
3. How difficult would it be to put notches around the hole to start the folds? (Like on the Tap-O-Cap)

I uave an aluminum plate with a tapered Jolene in it that I use to tighter my #11 (from the cap maker) down to #10. I have both sizes, but this process just gives me better product.

Somebody please make a punch and die for musket caps!

Well, I think I can call this a success. I got the brand new CVA nipples from TOTW today, and the caps I have made fit them exceedingly well. They are a nice tight fit. Firm pressure to seat, and, truth be told, a little hard to pull off of the nipple, although I expect that to change when I fire them.

The problem is, I didn't keep track of the specific method or specific tooling I used to make these caps, as I was more concerned with the process of forming process than with tracking the individual caps I formed, so they were just jumbled up all in a pill bottle. Some very few of them were made with a small plunger or mandrel, and they don't fit # 11 nipples. They might fit #10 revolver nipples, but I don't have those to test.

Now I need to mix up some Prime-all and load these up. I was going to test them on my guns, but I don't want to have to clean the barrels repeatedly I over the course of a testing program. So I got these nipples to rig up in a test firing gadget I will build

I was trying to figure out how to make a hammer to strike them, and had several designs, but didn't like any of them. I thought, "I have to build a better mousetrap," and it hit me! I will use a mousetrap as the hammer! So I'm going to rig something up to do just that. That way I can test the caps, and maybe do a corrosion test of the Prime-all compound on one of the nipples, too.

So I will say that it is cheap and easy to make caps with homemade tools from the hardware store or that you have in the garage. How cheap are the tools? 40¢ for a nylon spacer, and maybe 20¢ for a #10 wood screw, plus some scrap wood for the handle.

I like the .002" and .003" brass better than the aluminum for the caps. It forms in the die absolutely easily, while the aluminum is much more finicky and prone to punch through by the mandrel. With the brass, you just center your disk on the die and push down on the mandrel, and there you have a nice golden cap.

I'm also going to fool with molding a die from HDPE plastic (milk jug plastic), but that's going a bit beyond "simple tools in hand," so it will be a different kind of project.

Edit: It wasn't clear above... I'm going to make up some new caps using the final method I developed, so that I can test that process. I think most of the aluminum caps, and almost all of the brass caps were made using that method, but I want to be certain, so that I can be more...scientific?...about judging my results. I will make a detailed how-to post after I have completed my testing.