I used to know this, honest !

[watkibe]

Thanks for all the widely divergent responses. I also thank those who expressed concern about my safety, due to my virtually complete ignorance about casting bullets.
I suspected (sorta remembered) that a cast boolit can often be safely substituted in a recipe for a jacketed bullet if the bullets are the same weight.
Onandaga, I always respect the info in your posts, and I thank you for tracking down Modern Reloading, second edition 2. Thanks.
I not only have the second edition, but the first edition as well; I bought it when it was first published.
On occasion I ask a "dumb" question just to stimulate interesting responses, and maybe learn something along the way. This was not the case with the question that started this thread. I just wasn't able to trust my memory on that point, and my patience with looking through all my manuals and notes had gotten somewhat thin. Ummm, what to do ? "I know", I thought, "I'll ask the good folks on CastBoolits." As expected, I got several answers that answered my question. Quite unexpectedly, I was also called inexperienced, and ignorant.
After reloading and casting boolits for almost 30 years, the "inexperienced" charge is dismissed. As for stupid: I was in grammar school when my IQ was tested. The result was 160 on the Stanford-Binet test. (on this test, 70 to 130 is considered "normal").
So, to one and all, whatever your motivation, thank you for sharing.

[firefly1957]

You need to put in caliber when you ask such a question! One of the problems that cast boolits run into in bottle necked cartridges is when the base of bullet is below case neck the bullet can rivet causing high pressure. Also lead acts different at high speed then copper if you want to test this put a ingot of lead in a vise and go at it with a hack saw then try as thick a piece of copper as you can find. Even though lead is soft you will find it is harder to cut than copper it has to do with the properties of each material. Or you can try the same in a drill press with smaller pieces of lead and copper.

[onondaga]

cbrick pointed out in #19 that jacket material is about BHN99. Our cast bullet alloys get no where near that. Many in the casting community, including some members here believe The BHN to load pressure relationship theory presented in the Lee manuals is hogwash and that ultimate compressive strength of bullet alloys does not translate to an area of accuracy sweet spot in a cast bullet load as Lee projects.

I do believe Lee and have repeated his testing procedure numerous times when working up cast loads.

Physically getting that experience under my belt has been a help to me in understanding a relation of the jacketed bullet to the cast bullet regarding the pressure of loads and the window of crossover between cast and jacketed loading data.

Those chapters in the Lee book on alloy BHN and load pressure are the most difficult to study and learn if you don't do the experiment and take an opportunity to prove Lee right yourself. There are so many new casters and so many old casters that are only interested in published load data and results that ignore the theories and only want group size. They don't do themselves or their firearms justice by not really working up loads with alloy and fit.

Jacketed bullet data can be helpful to you if you understand its relation to your cast boolits in your alloy.

Gary

[Char-Gar]

When it comes to things that might blow up in your face, memory is always suspect. The older we become, the more suspect it is.

Experience only counts, if we learn and can recall what we learn. There are lots of folks who have done things wrong for a very long time. They seem to be unable to learn from their mistakes.

High IQ only counts, if it helps us get through life with success. There are lots of very bright folks who don't have enough common sense to come in out of the rain.

The above is just my musings on this very rainy day in deep South Texas. It is not intended to speak to any individual or issue. Just some random thought from a gabby old fellow.

[onondaga]

A lot of us with the high IQ sometimes forget that IQ is only a potential and that the ability to achieve is something altogether different. Yes, I tested higher than the level you mentioned even as an adult, but achievement level in my life has taken wide variation generally dependent upon my desire or need to accomplish and of course, in my life, personal health has been a large factor.

Gary

[Char-Gar]

Intelligence is just one of the tools we humans have in our bag of tool to live life. Like any tool, it only has value to the degree and how it is used. It only is important if it is used for a valid goal. Hitler was one smart dude!

The same is true of education and most every other tool in our bag. A successful life often has little to do with either intelligence or education. Both tool are to be used and not worn as a badge to impress others and set folks higher on the food chain.

Just saying....

[44MAG#1]

mmmmm

[cbrick]

When it comes to things that might blow up in your face, memory is always suspect. The older we become, the more suspect it is.

No kiddin, I have always been an advocate of good notes both with handloading and bullet casting. Any more every day older I get the more important these notes become and the more detailed I need them to be.

Rick