Craig, I think you need to re look at the heavy loads in the 44 vs the 45 & I'm not talking about 5 shot cylinders. I may have to look for it but in a long ago article by Ross Seyfried titled, I think " Turbo Charging the 45" something like that he made it pretty plain that the 45 at 32,ooo & heavy cast slugs was out performing the 44 maggie at 40,000. Again, this was with 6 shot guns & only heavy weight bullets. The standard weight slugs were pretty much a toss up. And 100 fps with BIG bullets is a fair amount.
As for the cases with the cannelure I reserve them for 9 grs. of Unique & don't think I've ever thrown one away & most are several years old. It usually irons out after 3-4 firings as most on here know.

Dick