Diggers: Your question suggests that you are interested in understanding ballistic theory and how it relates to reloading one's own ammunition. I've looked for the same materials myself, hopefully written for the literate layman and not exclusively for the Englineering Major.
The closest I've come to an overview is in
here . For more info on
internal ballistics,
see this sub-article .
So far, other than a very fundamental understanding of pressure issues, I've gained little in this quest. The point is,
for most reloaders it is probably more important to take a 'cookbook approach' and learn the physical techniques of reloading and accept published load data, rather than working from a theoretical perspective and 'drilling down.'
I initially settled on the Hodgdon Burn Rate chart--found
here . However, my attempts to understand VMD (density) characteristics lead to finding
this chart--which is remarkably similar to the Ramshot chart
Crimp linked to.
I still don't have the slightest idea how to use this information, but father frog's summary does have some bullet points that help. Consequently, I am back at focusing on an intimate knowledge of recipes and components combined with the actual performance from a given firearm.
In summary, stay with the manuals mentioned above and glean from them what you can. Richard Lee provides good information, even if his style is a bit egocentric.
(I've not worked with 44 Mag, but I have worked extensively with 38 / 357 'replica reloads' for PD rounds in 2" barrels, even to the point of 'translating' 38 recipes into 357 cases and exploring a couple of powders that do not have much (if any) published data for use in those cases. But, I stay within conservative guidelines, and I rely on chrono data to help guide me.)
Sam Adams: As for how often a case can be reloaded--it varies widely, given the expected parameters. As a rule of thumb, I figure ten reloads with medium-pressure recipes
with new Starline cases, and anything beyond that is a bonus.
I have some .45ACP brass that has been mostly / exclusively used for lowball loads that have the headstamp worn off--I'm sure they've been reloaded 50-100 times or more--and still work fine for plinking. OTOH, I've had 10mm cases give up (split) after less than five reloads with upper-end (NOT max) loads. The one cartridge case I consider problematic is .40 S&W, but I have not reloaded for it recently.
sourdough44: I think you are talking about the "magnum" handgun powders (H110, W296) and not all 'slow burning' handgun powders, such as AA#7, Silhouette, etc., etc. This is kind of a quibble, I know, but there is a broader recipe base for slow powders as opposed to the limited range of the magnum powders.
Jim H.