Making Caps

I worry about the limited availability of buying caps. I've collected a fair number of PFC guns, and I like to shoot them all. However, after each shot I realise my cap stock goes down. That makes me consider... To shoot or not to shoot, that is the question.

I'd like to be a able to fire away with peace of mind knowing that I don't have ration my fun, but the limited availability of suppliers bothers me. So I do ration my caps.

I have a solution, but I don't have the knowhow to realise that solution. Having said that, I do have part of the solution. I keep all my used caps. I'd like to refill those used caps, but I don't have the recipe to make whatever the Japanese puts in them.

How can I find that recipe? You'd think with all the incredible modern information based platforms, like YouTube and Google, you'd find a wide selection of DIY cap making helps. If there are any, I haven't found them. Anyone got any ideas? Or is this just a smokeless pipe dream!

Hi Catweazle,
I have also wondered about making my own caps. The good thing is, you're keeping your used ones. I do the same. I have done experiments in the past, reusing spent caps and filling them with the powder from ring or roll caps (the sort you can get a lot for with very little cost).
The tricky part is extracting the powder without setting it off as it is very sensitive to shock. The best method is to soak the caps in water and gather up the powder in a clump and let it dry. While it's wet and malleable, you can place it into a used 7mm cap then wait for the water to evaporate. Obviously, some model guns will leave a hole in the used caps so this only really works with those caps that remain intact (such as the ones used in MGC style cartridges, as the Marushin design relies on the cap bursting to vent the pressure).
I have found that all 8 caps from a plastic ring cap or 10 paper roll caps is roughly equivalent to the power you'd get in a standard 7mm cap. For the same price, you get a lot more "bang for your buck" but at the expense of performance. Paper caps for example always seem to have a discrepancy in power per charge.
Then, there are matches. It is possible to make shock sensitive powder by mixing powdered match heads with scraped powder strips from the side of the match box but it can be very tricky to get the ratio correct.
One thing I have done in the past is super glue a very small piece of metal to the centre of a used 7mm cap and then place a single paper cap on top of it, using a piece of masking tape to hold it in place. Then, using the powder from 6 match heads, I fill the cartridge after placing a cap in it. This way, you don't have to mix the striker powder off the match box because your single paper roll cap acts as the shock sensitive compound that ignites the match heads.
While this method can work, it is highly corrosive, more so than standard caps even. There are other options, however, depending on what is legal in your jurisdiction. For example, I know there was a guy who made custom cartridges (high-performance cartridges) that actually used small pistol primers instead of caps. The quality control and reliability is obviously a lot better than the standard Model Gun caps but you have the issue of legality to deal with

S. Thomas wrote:

Hi Catweazle,
I have also wondered about making my own caps. The good thing is, you're keeping your used ones. I do the same. I have done experiments in the past, reusing spent caps and filling them with the powder from ring or roll caps (the sort you can get a lot for with very little cost).
The tricky part is extracting the powder without setting it off as it is very sensitive to shock. The best method is to soak the caps in water and gather up the powder in a clump and let it dry. While it's wet and malleable, you can place it into a used 7mm cap then wait for the water to evaporate. Obviously, some model guns will leave a hole in the used caps so this only really works with those caps that remain intact (such as the ones used in MGC style cartridges, as the Marushin design relies on the cap bursting to vent the pressure).
I have found that all 8 caps from a plastic ring cap or 10 paper roll caps is roughly equivalent to the power you'd get in a standard 7mm cap. For the same price, you get a lot more "bang for your buck" but at the expense of performance. Paper caps for example always seem to have a discrepancy in power per charge.
Then, there are matches. It is possible to make shock sensitive powder by mixing powdered match heads with scraped powder strips from the side of the match box but it can be very tricky to get the ratio correct.
One thing I have done in the past is super glue a very small piece of metal to the centre of a used 7mm cap and then place a single paper cap on top of it, using a piece of masking tape to hold it in place. Then, using the powder from 6 match heads, I fill the cartridge after placing a cap in it. This way, you don't have to mix the striker powder off the match box because your single paper roll cap acts as the shock sensitive compound that ignites the match heads.
While this method can work, it is highly corrosive, more so than standard caps even. There are other options, however, depending on what is legal in your jurisdiction. For example, I know there was a guy who made custom cartridges (high-performance cartridges) that actually used small pistol primers instead of caps. The quality control and reliability is obviously a lot better than the standard Model Gun caps but you have the issue of legality to deal with

Some great tips there. Thanks. I've seen how to make impact powder on YouTube using matches, but it's time consuming and laborious. It would be a lot easier with strike anywhere matches, but those are things of the past and no longer available. Cartridge primers are impossible to get in the UK.

What I would really like is to make the proper stuff that the Japanese use in their caps. You can get DIY instructions on just about anything on YouTube. I could make black powder if I wanted to, lots of videos on that, but nothing close to what is needed for PFC caps. I'd love to discover the manufacturing methods and ingredients for the Japanese Real Flame caps that Plugfirecapguns sell. With a 3d printer and the powder recipe, my worries of the caps becoming totally unavailable would disappear in a puff of smoke. Pun intended lol.

I remember used to when we had the strike anywhere Swan Vestas. Now, they're all safety matches. Really, that leaves the cheap paper/plastic caps as the only option. I'm not sure but aren't shotgun primers legal to purchase without a license? It's only pistol and rifle primers that require a certificate I think in the UK. Could be wrong. I mean, our laws our strange. You can get blank ammunition no problem whatsoever but you can't get primers even if you just wanted to reload blanks at home (which I have done using a paper roll cap in the original primer, about 14 match heads, packed down with toilet paper)

As for making the actual cap body, while 3D printing is an option, it depends on what filament you use as the cap body has to be fairly thin and flexible. I'm currently looking into making caps from recycled HDPE (Milk Carton) plastic. When heated with a hot air gun, it becomes very malleable so you can then form it on a mould to make the caps.
I'm currently doing all sorts of experiments with making my own cartridges, parts and caps so I'll let you know how I get on.

S. Thomas wrote:

I remember used to when we had the strike anywhere Swan Vestas. Now, they're all safety matches. Really, that leaves the cheap paper/plastic caps as the only option. I'm not sure but aren't shotgun primers legal to purchase without a license? It's only pistol and rifle primers that require a certificate I think in the UK. Could be wrong. I mean, our laws our strange. You can get blank ammunition no problem whatsoever but you can't get primers even if you just wanted to reload blanks at home (which I have done using a paper roll cap in the original primer, about 14 match heads, packed down with toilet paper)

As for making the actual cap body, while 3D printing is an option, it depends on what filament you use as the cap body has to be fairly thin and flexible. I'm currently looking into making caps from recycled HDPE (Milk Carton) plastic. When heated with a hot air gun, it becomes very malleable so you can then form it on a mould to make the caps.
I'm currently doing all sorts of experiments with making my own cartridges, parts and caps so I'll let you know how I get on.

Great video. I have blank guns, both 9mm and 8mm. The thing with blanks though is that they are too loud. I only fire them on Bonfire Night and New Year, they would be a nuisance any other time of the year. PFC caps are just right I think, you can shoot them indoors, which is not recommended with blanks.

I have tried percussion caps which are legal to buy. However, they are in a hard copper shell and don't work. I have a Denix 1825 Italian cap-lock pistol that has a really strong hammer spring, that's the only gun that works with percussion caps.

Good luck with your experiments, and I would indeed like to know how you get on with them.

I have tried this. I always keep my spent 7mm and 5mm caps in a empty family pack chewingum container. I fill them up with capgun insides (8 are about right) or, even more powerfull, the small amount of powder in wire pull kids fireworks.
Its quite powerfull.

Rob du Jour wrote:

I have tried this. I always keep my  spent 7mm and 5mm caps in a empty family pack chewingum container. I fill them up with capgun insides (8 are about right) or, even more powerfull,  the small amount of powder in wire pull kids fireworks.
Its quite powerfull.

I've never seen those pull kids fireworks. Do you know where I can get them?

I found this video the other day, might give you guys some ideas!

Just skip the part about the fuses and all that and check what he do with the caps!

https://youtu.be/RmvPWcPb4Zk

That IS interesting..............
I don't think I would ever use it to make caps, but making my own "prop powder" to enhance effects could be something I might try in the future.
Cool find!

Sommarkatze wrote:

I found this video the other day, might give you guys some ideas!

Just skip the part about the fuses and all that and check what he do with the caps!

https://youtu.be/RmvPWcPb4Zk

Success... This works a treat. The only thing I don't get from the video is where he scratched the strip setting some off. That is not necessary. Just soak the strip in warm water for a few seconds, peel of the top layer, then collect the compound with a craft knife and transfer to the empty cap held in the simple wood jig. Press to firm with a plastic or wood tool. No need to put paper in the cap as he did, they dry out firm.I let them dry out for two days.

I use 20 paper caps for the 5mm caps and 25 for the 7mm caps. That gives a very satisfying loud bang.

Thanks for that link.

I Think he scratched them just to show how sensitive the caps were

But alright no problem! Great to hear it turned out to work!

Sommarkatze, where is the video? Link to YouTube says it was removed. Can you repost it?

The uploaded has removed it. It was very simple though.

Visualise that a strip of paper caps has a thicker strip of paper on the bottom, dots of compound on top of it, and over the compound a very thin strip of paper is laid to keep everything in place.

Take a strip of caps - say 15
Dip the whole thing in warm water for a few seconds
Lay the strip on a table, with the compound dots facing up
With tweezers, gently coax the very thin top layer of paper off. This leaves the compound dots uncovered.
With a thin object - eg modelling knife blade, scrape off the compound dots. The come off easily and are damp.
You can then refill a used cap, gently tamping the compound down and leaving it to dry for a few days.

In the video the guy used a wood jig - a shallow 7mm hole in wood to hold the cap for tamping. He put a thin bit of paper over the compound to hold it in.

This worked very well for me on a model with a strong spring (revolver)

oozlum wrote:

The uploaded has removed it. It was very simple though.

Visualise that a strip of paper caps has a thicker strip of paper on the bottom, dots of compound on top of it, and over the compound a very thin strip of paper is laid to keep everything in place.

Take a strip of caps - say 15
Dip the whole thing in warm water for a few seconds
Lay the strip on a table, with the compound dots facing up
With tweezers, gently coax the very thin top layer of paper off. This leaves the compound dots uncovered.
With a thin object - eg modelling knife blade, scrape off the compound dots. The come off easily and are damp.
You can then refill a used cap, gently tamping the compound down and leaving it to dry for a few days.

In the video the guy used a wood jig - a shallow 7mm hole in wood to hold the cap for tamping. He put a thin bit of paper over the compound to hold it in.

This worked very well for me on a model with a strong spring (revolver)

I've now refilled about 100 caps, both 5mm and 7mm. I'm really pleased with this and it works out cheaper than buying the Japanese caps. I've started buying paper roll caps in bulk, which makes it even cheaper. All you need are simple wood 5mm and 7mm jig, a craft knife, 5mm and 7mm dowels to press down the compound in the caps and that's it. Note: No need to place paper in the caps as they dry set, just like the Japanese caps.

Thank You Gentleman, I will give it a shot!