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denul
09-11-2009, 09:42 PM
This is a report regarding output using a 22-pound lead hot and 3 molds.

In almost exactly 90 minutes, I had emptied the pot completely. I started with a .45 200 gr hollow point, and .45 200 gr swc, both ordered from by miha. After the pot was about half-empty, production slowed, because of having to wake for the two cavity brass hollow point mold to cool, as well as the 6 cavity swc. So I got another group buy mold, the .357 Keith 173 gr from a year or so back.

I kept the pot set at 750 degrees consistently.

After pre-heating it in the pot it dropped good bullets on the first cast! I have never had that happen, although I have read about it. Timing myself, the 22-pound rcbs pot, loaded with straight ww, resulted in the following production. I returned sprues to the pot, and cast until the last of the lead ran out from under the thin layer of sawdust flux. I just wanted to see how long it would take to completely consume the pot full.

.45 200 gr hollow point (2 cavity, brass, miha): 6 pounds, calculated 210, actually counted 202, but found a sprue among the bullets.

175 gr Keith .357-(6 cavity, aluminum, group buy): 3.5 pounds, calculated 140 actual count 141

.45 200 gr swc - (6 cavity, aluminum, miha): 11.5 pounds, calculated, 400, actual counted 390 and again found to loose sprues laying around in the bullets.

All of this translates to a production rate of about 500/hr, not all that impressive.

At first, my rhythm included a single cast of the 6 cavity swc alternating with two casts from the brass two cavity hollow point mold. As both grew hotter, the delay for proper cooling to prevent sprue smearing increased, which allowed me to heat the .357 and start casting with it. By this time I had increased the ratio of brass casting from two to 1, to 3 casts for each one in the aluminum mold, because the latter was becoming hotter at a more rapid rate. This ratio seemed to just about perfect to allow appropriate cooing for the brass mold.

When I started with the .357, everything was going fine for a while, but then I started noticing cooling defects from the two initial molds which had been producing visually perfect bullets.

I am not sure if my hollow point is one of the Miha molds that other users reported growing whiskers, but these were evident as very tiny projections that stopped appearing after several minutes of casting with the third mold. I also started noticing minimal rounding of the very sharp edges that are characteristic of the swc 200 gr Miha mold, when it is at the proper temperature. Obviously, the increased time between castings from adding the third mold caused excessive cooling of the first two.

Since I am a plinker, old, and visually challenged, I will probably use these defective bullets as is. They still look good, but they are distinctly different from the better ones, and it is probably not much more trouble to produce higher quality bullets using rapid cooling methods.

Several points of interest here..

1.) One could probably get 3 different molds going if they were all very easy to overheat, which I have especially noticed, as have other users, in heavy 45/70 6 cavity aluminum molds. Probably the same would apply to heavy 6 cavity 45 Colt, or 44 magnum rounds, which many might prefer to have in higher volume than 45/70.

2.) Running 3 molds in no way increases productivity numbers ( there is more reaching around to pick up and lay down molds, but if one is efficient, probably not much more than using two molds), but it does increase the variety of bullets that can be produced at one setting. For most users, this will probably not be a reason to try using 3 molds simultaneously, because of the risk of cooling related quality loss. When cooling the molds with a wet towel, productivity from 6 cavity molds is quite a bit higher, in my experience. When using 2 identical 6 cavity molds, with wet towel cooling of both the sprue plates and the bases, I have seen higher production rates, but did not bother then to count or weigh the bullets. Will probably try that again soon and count results. Cooling has never caused any damage to molds that I have witnessed.

3.) The old baby scale from a doctor's office that I use to weigh these bullets registers accurately enough to calculate numbers of bullets cast based on nominal bullet weights, at least when they are cast of using wheelweight. I always wondered if one could calculate members of bullet based on bulk weights, but never had bothered to try. It works!

4.) His current difficulties notwithstanding, Miha has created two excellent molds that I am proud to own. I am definitely looking forward to his future production. I'm also very pleased with other group buy molds from Lee.

5.) The two cavity brass hollow point mold does not suffer much, if any, in terms of productivity. Like many others, I am looking forward to trying 4 cavity hollow point designs; I see no reason that they would not do as well as the excellent two cavity results we are now seeing.

6.) Bull plate is intriguing, and might be helpful in a situation like this; I have not yet put my order in for a supply.

Dale53
09-14-2009, 08:43 PM
Several months ago, in reading a past issue of the Handloader, Mike Venturino metioned that he had adopted an idea from a friend. That is, using a small manicurist's fan to cool the sprue (and incidentally, maintaining a constant temperature with the mould body). A lightbulb went on in my head ("ahah! Says I":mrgreen:) and I went looking. I found a small (5" or 6" diameter) fan at Target department store that cost all of $7.50. It was NOT in the cosmetic section but in the fan section of the store. I bought it and immediately clamped it to my casting bench so it is over the bench 8"-10". It is very quiet is does not irritate. I fill the mould, move it under the fan and in 2.0 seconds the sprue is ready to cut. The bullets lie under and to the rear of the fan so are constantly bathed in a cooling flow of air. That means I can pick up the bullets shortly after finishing casting. The mould temperature (whether iron or aluminum) is kept at an optimum temperature and much time and aggravation is saved from not having to wait on the sprue to set up.

This is truly a wonderful casting accessory. Thank you, Mike Venturino!

By the way, I was at WalMart picking up some charcoal and happened to walk by the fan section and they also had a similar fan for a few cents less. So, they ARE available and cost little.

This is far better for me, than using a wet rag or dunking a mould as there is nothing to handle and it is always in the correct place.

FWIW
Dale53