Mike W1
Active Member
Might as well stir up the air a bit as I usually end up learning something or another!
I'll confine my thoughts to DC molds as I do believe there's some things about larger molds that would require some different methods than on the smaller ones. I've no experience with brass molds either but understand they seem to require to need to run hotter than aluminum or iron ones do.
Col. Harrison wrote years back about experimenting with aluminum sprue plates and at that time most molds were iron. I've made a few of them and had pretty good results with them finding that they naturally shed some of the heat easier than the steel ones. A number of casters mention using fans to cool the sprue a little faster and I've long since used a combination shelf to rest the molds on and a small fan blowing onto the sprue plate. It has a easily accessible switch which I turn on when I feel the sprue starting to cut a little too easily.
Another caster I notice talks about priming the sprue plate to heat it before filling the mold to get good fill out which seems to be 180° from above. I suspect he's using aluminum molds but don't really know that for sure. To me good fill out of the mold has just indicated that the block itself be up to casting temperature for wrinkle free bullets. I get mine there on a PID controlled hot plate and first bullets out are good. IF....I ensure the lead flows into the center of the sprue hole because if I hit that sprue plate instead of the hole I can predict 99% of the time either the base will have a small void or it won't be fully filled. I noticed that many years ago. And as long as the mold is hot I do not find it necessary to have much of a sizeable sprue. It's a bit hard to control the flow on a Lee 10# as there's obviously a difference in flow volume when the pot is full compared to when it's a lot lower but I've seen a lot of good bullets when the sprue was not much larger than a BB. Usually cast them bigger than that of course and prefer to join the 2 sprues as it's easier to dump them that way.
That's the way things work for me. Don't have anything mold-wise for rifles as I kind of got away from them over the years but steady flow of alloy and center of sprue hole used to work just fine back when I did that kind of casting. Gent on the old CB-L that cast commercially wrote that stuff up much nicer than I ever could do. Like I said with larger molds it's likely that a hotter sprue plate might be necessary than on these smaller ones. First place it would seem to be it'd be hard to center the alloy flow and believe I've read the big gang molds were fed by pouring into some sort of v-trough which fed the cavities. Never seen one used so can't say on that.
Gave up ladels some time after deciding hair shirts weren't comfortable either but have often wondered if you use them in the method of putting the nipple to the mold and rotating if you aren't just maybe ensuring the flow hits the center of the sprue hole anyhow. Think some call that pressure casting and I suppose there's a theoretical advantage there. In fact some math inclined soul awhile back came up with some figures to show just that. But really I don't believe everything I read on the internet either!
But I can learn, and it should be interesting to see what this might stir up!
I'll confine my thoughts to DC molds as I do believe there's some things about larger molds that would require some different methods than on the smaller ones. I've no experience with brass molds either but understand they seem to require to need to run hotter than aluminum or iron ones do.
Col. Harrison wrote years back about experimenting with aluminum sprue plates and at that time most molds were iron. I've made a few of them and had pretty good results with them finding that they naturally shed some of the heat easier than the steel ones. A number of casters mention using fans to cool the sprue a little faster and I've long since used a combination shelf to rest the molds on and a small fan blowing onto the sprue plate. It has a easily accessible switch which I turn on when I feel the sprue starting to cut a little too easily.
Another caster I notice talks about priming the sprue plate to heat it before filling the mold to get good fill out which seems to be 180° from above. I suspect he's using aluminum molds but don't really know that for sure. To me good fill out of the mold has just indicated that the block itself be up to casting temperature for wrinkle free bullets. I get mine there on a PID controlled hot plate and first bullets out are good. IF....I ensure the lead flows into the center of the sprue hole because if I hit that sprue plate instead of the hole I can predict 99% of the time either the base will have a small void or it won't be fully filled. I noticed that many years ago. And as long as the mold is hot I do not find it necessary to have much of a sizeable sprue. It's a bit hard to control the flow on a Lee 10# as there's obviously a difference in flow volume when the pot is full compared to when it's a lot lower but I've seen a lot of good bullets when the sprue was not much larger than a BB. Usually cast them bigger than that of course and prefer to join the 2 sprues as it's easier to dump them that way.
That's the way things work for me. Don't have anything mold-wise for rifles as I kind of got away from them over the years but steady flow of alloy and center of sprue hole used to work just fine back when I did that kind of casting. Gent on the old CB-L that cast commercially wrote that stuff up much nicer than I ever could do. Like I said with larger molds it's likely that a hotter sprue plate might be necessary than on these smaller ones. First place it would seem to be it'd be hard to center the alloy flow and believe I've read the big gang molds were fed by pouring into some sort of v-trough which fed the cavities. Never seen one used so can't say on that.
Gave up ladels some time after deciding hair shirts weren't comfortable either but have often wondered if you use them in the method of putting the nipple to the mold and rotating if you aren't just maybe ensuring the flow hits the center of the sprue hole anyhow. Think some call that pressure casting and I suppose there's a theoretical advantage there. In fact some math inclined soul awhile back came up with some figures to show just that. But really I don't believe everything I read on the internet either!
But I can learn, and it should be interesting to see what this might stir up!
