CraigC,
Well, yeh, rechambering .45 LC to .454 Casull is unnecessary in this rifle,
IF you hand load. Much as I want to do that, and am studying up to begin, and shopping for used equipment, I have other responsibilities and cannot do it right now. And I want a powerful big-bore rifle right now (or in short order).
And I agree that most .454 Casull factory loads are well below SAAMI max, which is fine, because in most applications the extra margin would not matter. Steve Young (Nate Kiowah Jones), whom you've somewhat dismissed in a related post, does advise some mods to the recent-manufacture factory Rossi M92 .454 Casull if you're going to use heavy .454 Casull loadings a lot. But these are for extending extending operational lifetime, not for metal-rupture safety.
Yes, so I suppose I could buy a factory Rossi M92 in .45 LC and use the most powerful factory +P factory .45 LC loads I can find. I gave a few examples over on a concurrent thread:
Rossi .45 Colt....16" or 20"? at
http://www.thehighroad.org/showthread.php?t=684852, specifically post #7 (
http://www.thehighroad.org/showpost.php?p=8509531&postcount=7), which is about some offerings from Double Tap Ammo. Then, if those are not powerful enough, I can upgrade when I get into reloading, finally.
Or I could rechamber a .45 LC to .454 Casull and just use factory .454 Casull ammo, some of which I already have. You discourage that strongly. Other than the reason that it is innecessary, what other reasons do you have?
Anyway, until then, I am building up a nice store of once-fired .45 LC and .454 Casull brass!