Harry O
09-28-2009, 09:03 AM
I am getting faster. These are from a Rapine single-cavity, hollow-base mould for the 41 Long Colt. I have to cast them as hot as my pot will go and separately heat the center pin over a candle every 4th or 5th bullet.
I started out at about one-per-minute with this mould several years ago. Then I worked up to 1-1/4 per minute. Since then, I changed the length of the pin to up it from 188gr to 218gr. Yesterday, it worked out to 1-1/2 per minute (I am not saying that changing the pin make it faster). That is also why I don't cast these for resale. I could not charge enough to make it worth my while to cast them for others.
Actually, I credit the Rapine mould as being an easy to cast with mould. Not just this one, but all of Rapines I have. It is aluminum, like many others. The NEI moulds I have are also aluminum, are larger, and are almost, but not quite as easy to cast with. The Lee moulds are also aluminum, but are much smaller, and of course, they don't cast nearly as well as the two larger ones. It looks to me like the right amount of aluminum is the amount that Rapine uses. If they don't do that, larger is better than smaller.
Anyway, I lubed about half of them and will be loading them tonight. That should give enough to get some data to compare with my past 41 Long Colt data. A quick test of 50 or so I had a couple of weeks ago looked like it had good possibilities.
P.S. I got started casting on a Rapine hollow-base mould for the 41 Long Colt. Since then, I have cast approx 6,000 - 8,000 hollow-base bullets from about 8 different HB moulds I have. I know what it takes to cast them. I have noticed that some of the things I do for HB moulds, I have started doing when I cast with plain-base moulds. It slows things down, but I seem to have more consistent weight and fewer rejects doing this, even with PB moulds.
One of the things I do is run it hotter than I hear people around here use for their moulds. I try to keep it hot enough that the sprue takes at least 3 seconds to flash over (5 seconds for HB moulds). I want to get a depression in the sprue lead over the hole once it hardens. That means my bullet is more consistent in weight (I have some data on that if anyone is interested). I have gotten pretty good at holding the mould level until the sprue flashes over, even when doing other things (like looking at the last one cast to see if they go into the reject pile or keeper pile).
I also don't flux much. I melt everything, heat the mould and sprue plate by dipping them in the melt, then flux, and then cover the top of the melt with boric acid. That melts over the top and keeps oxygen away from the melt. Because of that, I cannot dump scrap back in as I go along. I keep it in a scrap pile. When the melt gets low, I clean out the old boric acid, add all the scrap, then replenish the pot with ingots. When everything is melted, I reheat the mould and sprue plate again, then flux again, and cover the top with boric acid again. No, I don't run the pot as hot for PB moulds (as I do with HB moulds), but I run it hot enough that boric acid is a help.
I started out at about one-per-minute with this mould several years ago. Then I worked up to 1-1/4 per minute. Since then, I changed the length of the pin to up it from 188gr to 218gr. Yesterday, it worked out to 1-1/2 per minute (I am not saying that changing the pin make it faster). That is also why I don't cast these for resale. I could not charge enough to make it worth my while to cast them for others.
Actually, I credit the Rapine mould as being an easy to cast with mould. Not just this one, but all of Rapines I have. It is aluminum, like many others. The NEI moulds I have are also aluminum, are larger, and are almost, but not quite as easy to cast with. The Lee moulds are also aluminum, but are much smaller, and of course, they don't cast nearly as well as the two larger ones. It looks to me like the right amount of aluminum is the amount that Rapine uses. If they don't do that, larger is better than smaller.
Anyway, I lubed about half of them and will be loading them tonight. That should give enough to get some data to compare with my past 41 Long Colt data. A quick test of 50 or so I had a couple of weeks ago looked like it had good possibilities.
P.S. I got started casting on a Rapine hollow-base mould for the 41 Long Colt. Since then, I have cast approx 6,000 - 8,000 hollow-base bullets from about 8 different HB moulds I have. I know what it takes to cast them. I have noticed that some of the things I do for HB moulds, I have started doing when I cast with plain-base moulds. It slows things down, but I seem to have more consistent weight and fewer rejects doing this, even with PB moulds.
One of the things I do is run it hotter than I hear people around here use for their moulds. I try to keep it hot enough that the sprue takes at least 3 seconds to flash over (5 seconds for HB moulds). I want to get a depression in the sprue lead over the hole once it hardens. That means my bullet is more consistent in weight (I have some data on that if anyone is interested). I have gotten pretty good at holding the mould level until the sprue flashes over, even when doing other things (like looking at the last one cast to see if they go into the reject pile or keeper pile).
I also don't flux much. I melt everything, heat the mould and sprue plate by dipping them in the melt, then flux, and then cover the top of the melt with boric acid. That melts over the top and keeps oxygen away from the melt. Because of that, I cannot dump scrap back in as I go along. I keep it in a scrap pile. When the melt gets low, I clean out the old boric acid, add all the scrap, then replenish the pot with ingots. When everything is melted, I reheat the mould and sprue plate again, then flux again, and cover the top with boric acid again. No, I don't run the pot as hot for PB moulds (as I do with HB moulds), but I run it hot enough that boric acid is a help.