I am pleasantly surprised at all the replies to my question. I will attempt to address them all in order.
I have now read, and been informed by p.m., that the cases I mentioned will have to have the case rims thinned by about .005". A "simple lathe job" is not simple if you don't have a lathe. I hope to avoid that, but may not be able to.
These are the cheapest cases I have found, and as I understand it come with the front half of the case already annealed and ready for fireforming.
https://www.grafs.com/retail/catalog/product/productId/76364 I really don't think I want, or need, all brass cases longer than 3". Though no one has come up with an actual comparison of case capacity between current plastic 3" cases and these 9.3 X 74R brass cases I cannot help but believe it will be at least 5% increased case capacity, maybe more. That will do what I want to do (though I may someday get greedy and go for the gold, as my friend Bill suggests).
And, as Bill mentions once again, I have absolutely proven that very long shot columns can pattern extremely well. And, before someone points out the obvious that patterns are two dimensional and don't take into consideration the longer shot string, I use them on doves and they are deadly. Straightaway shots don't prove much actually, in regards to shot string length, but crossers do.
Thanks to all for the excellent replies and information.
