Month: April 2003

Die Making

Posted by on April 21, 2003

I’ve made dies, in particular bullet sizing dies for cast bullets. These aren’t too difficult. Nor are loading dies for straight cases for that matter. As you say the cost bottleneck is the reamers. I’ve made dies with a carefully made boring tool but the result, though workable, isn’t as good as a reamed die. The problem is that no fixed reamer is available for any of the sizes required. The only type that will do the job is the adjustable type. I have two of these, which work very well, but at R 450 each they’re too expensive for occasional use. But a straight die for the 45 – 90 and other straight cases can be done with a boring tool and a lot of careful polishing if necessary.Tapered cases and bottleneck cases are a different matter entirely. The only practical way of making these is to make one’s own reamers, which is very difficult work for the average hobbyist. That’s what I meant by it not being worthwhile even at current prices.Not only BP flash holes are 2mm, most others are that size, and most decapping pins seem to be about 1.80mm. I made my expander rod and decapping pin one piece because it seemed easy. Most decapping pins are much too long. I made mine only about 10mm, because the shorter it is the better it will resist bending or breakage. But your method of using a drill as a decapping pin and gluing in place is a good one. The pin should be slightly smaller than the flash hole, so I’d recommend a 1.80mm drill, and I’d recommend gluing it into it’s hole with Loctite.I’m also glad to have your comments on your bullet casting methods, John. I’m a believer in keeping things simple so your use of a simple gas heater makes sense. I am somewhat surprised that you are getting a lot of slag and dross, at least your posting gave that impression. I know of course that you cast for BP which is rather different from other bullets. In particular, it is almost pure lead so the melt temperature is considerably higher than would be used for other bullets, and high temp is the usual culprit of high drossing levels. Nonetheless I wouldn’t expect high drossing with almost pure lead. I can only suggest casting at the lowest temp that will cast properly and see what happens.The professionals use simple and cheap fluxing methods, usually sawdust thoroughly stirred into the melt, which floats the dross to the top. I’ve never heard of using potatoes or such things as solder. The use of such things as beeswax and candle wax are mainly an amateur thing, because sawdust isn’t practical for small quantities. Drossing shouldn’t be a problem if the temp is right. If you’re using pure lead, melt temp is about 630F. Casting temp shouldn’t exceed that by more than 100F. I’d suggest 700F. At that temp you shouldn’t have a big dross problem.I use cheap candles for drossing. I drop a 30mm length into the melt and encourage it to flame by vigorous stirring with a big ladle. If the first lump doesn’t flame a second lump usually does the trick.I should point out however that I find it seldom necessary to flux. My big electric pot holds 15kg of alloy and I might flux it once in a week’s continuous casting, which I do only when I have a considerable amount of lead sludge on top of the alloy. But then I’m using clean foundry ingots. Scrap is a different story and will usually need more fluxing.The cause of drossing and the mechanism of fluxing isn’t fully understood. Dross usually takes the formof sludge on the top of the molten alloy. A lead sludge that is, in which the dirt is encased in the lead and can’t be separated without fluxing. The little fire caused by the candle wax separates the lead from the dirt, which can then be skimmed off. Most texts warn not to allow it to flame but I found it works best. Of course, those who don’t mind the loss of some alloy can skim off the lead sludge, in which case there’s no need to flux.[Originally posted to SATalkGuns -- Admin]