cap making dies

[Baron von Trollwhack]

You would have to inquire with the Swiss powder people on fineness of their powders. The "crushdown powder" I make with a small mortar and pestle is finer than ffffg. I use Goex. McMaster Carr has bronze screens you can put in an embroidery hoop to sift with, once you find out grain size data. But practically for this discussion a dust black powder under a cap in a foil new made cap shell will work with dust powder, and avoid stacking those toy caps to get the ignition power needed. Before I got my M & P I used am empty round shoe polish can and a 1" wooden dowel piece to crush powder, Gently. A little tedious, but workable.

BvT

[ofitg]

Speaking of available ingredients, i went with chlorate, sulfur and grit, works fine pressed into a copper cap, it even fires combustible cartridges, which surprised me, i didn't think it had that much zip. It's not the recipe i want to stick with since it's pretty dirty, but i wanted something to test the caps with, so went with what i had and was pleasantly surprised.

That's pretty cool!

[wicket]

Have moved up to chlorate, sulfur, and grit with added tin sulfide as a substitute for antimony sulfide. Banging the mixture on a steel plate with a hammer doesn't set it off, neither does grinding it on the plate with the face of the hammer. The formula detonates reliably with about the same bang as a commercial cap, the petals are opening on the caps and the notch on the hammer face is leaving the usual mark, but so far none of the caps has come apart.

[dondiego]

wicket - Can you supply the chemical ratios of the cap mixture please?

[ofitg]

Wicket, did you make the tin sulfide? If so, how did you do it? Thanks!

[wicket]

50.4 % potassium chlorate
26.31 % tin sulfide
8.76 % sulfur
12.39 % ground glass

[wicket]

I purchased a roll of pure tin solder from the hardware store, melted it into an ingot, and broke it down into granular tin using a rasp. I prepared a crucible with lid from thin-walled steel pipe, and placed a mixture of 40% sulfur and 60% tin by weight in the crucible, set the lid on the crucible (the lid should fit well, but not so tightly that gasses cannot exit the crucible) and heated the pipe with a propane torch until i got a sustained reaction between the sulfur and tin. Do this outdoors or under a fume hood since plentiful sulfur dioxide is produced. Expect some sulfur to burn around the edge of the crucible lid. After the crucible cools, it should contain a frothy looking black glassy substance in the bottom of the crucible. The walls of the crucible may be coated with sublimed sulfur, scrape it off and discard. Grind the point off a flat "Speedbore" type wood bit, and use it chucked into a drill to break up the tin sulfide. Don't try to make the bit fit the inside diameter of the crucible, you want it loose so it can rattle around a bit. I screened my tin sulfide through a 60 mesh sieve obtained from a place that sold pottery making supplies; crushing the pieces that weren't pulverized by the drill bit in a mortar and pestle.

[dondiego]

I have some antimony sulfide on hand. Would that be used in the same ratio as tin sulfide?

[wicket]

Same ratio, tin sulfide was substituted for the antimony sulfide originally used in the formula. Since you have antimony sulfide on hand it is probably safer to use it than to experiment with tin sulfide, nobody seems to know much about tin sulfide in primer compositions.

[wicket]

See whether this comes out as a picture of my cap dies and press setup.

[ofitg]

That's very ingenious! So you feed a copper strip into the machine, operate the lever, and a finished cap falls out?

If you ever want to sell copies of the machine, I'll bet you could find a number of buyers.

[wicket]

I imagine somebody with a bit of experience at tool and die making could come up with something a bit less clunky. I'm just happy to have caps that fit my revolvers, was sick of driving all over the place to find caps, and having to settle for #11's when i did find any. It's kinda fun pulling the lever and having a cap drop out, reminds me of a slot machine.

[swathdiver]

Wonder if that could be made into a "die" and used on reloading presses?

Replicate the Remington #10 but slightly less prone to come apart to keep Colts running and the cap and ball sixgun crowd would be swimming in gravy!

[wicket]

I think you're on the right track Swath. All i had to work with was a drill press, but with a lathe, a reasonably skilled machinist (i'm just a carpenter) could turn the sections of the die as cylinders, which opens up a lot of possibilities. I don't reload cartridges, so don't have a reloading press, at forty bucks a cheap arbor press from Harbor Freight seemed a workable alternative. I haven't blown the petals off any caps yet or had a jam, and i've fired hundreds at all sorts of charge weights during testing. In A Practical Treatise On The Fabrication Of Matches, Gun Cotton, Colored Fires And Fulminating Powders H. Dussance mentions that back in the day ten ounce copper was used to make caps, that's around 13 mil, modern caps appear to be formed from 5 mil, and i compromise with ten mil copper.

[swathdiver]

Hey Wicket, you've done a great job with this. I don't reload either, was thinking of the Lee single stage press which is about $30, it can be used for other things like sizing conicals and lubing them, testing lead, etc. Sounds like you've already determined the sweet spot with regards to cap material thickness too!

Two dies could be offered, one mimicking the Remington #10 and the other the CCI #11 which generally corresponds to Pietta revolvers for the former and Uberti and Treso for the latter, well, someone more knowledgeable than I could determine that but that's the idea. And let's not forget those old #12s, #9s and long #11s for rifles and smoothbores.

Have you reported on their fit and performance in this thread or somewhere else?

[wicket]

Swath, i haven't said too much about fit and performance. The plunger that forms the finished cap for a factory Pietta cone is .150", filed down from some scrap spring steel i salvaged from a discarded mattress. The cap fit is excellent, better even than a Remington # 10, because i use softer copper and a longer cap and don't have to hammer set the caps or use a push stick. I'll take some pictures of fired caps, and some detail shots of the dies and post them here. I can't stress enough that making the dies was not rocket science, the toughest part was coming up with a way to press the clover leaf cutter first, then the cup die, and then extract the whole plunger unit so that the copper strip could be advanced for the next cap. To switch from a Remington # 10 to a CCI # 11 would probably only require a double-ended cup plunger and a separate female die bored for # 11.

[wicket]

The die parts plus some new caps and fired caps. The steel thing with all the holes in it is a cap filling tray to control charge weight and speed up charging the caps.

[Mustangpalmer1911]

That is sweet wicket. Any interest in making and selling them?

[wicket]

Hadn't really considered manufacturing and selling cap dies Mustang. My interest in making the rig was to finally cut the last link between me and the merchants and nanny-staters who keep intruding themselves into my recreational shooting. What i was going for was something a shooter could make for himself out in the garage with some hand tools and an electric drill; sort of like posting about making homemade powder.

[Rojelio]

wicket, I'm confused about how your tool operates. Does the center rod in your punch slide up and down?