Look at the schematics of both cases. I am computer illiterate, or I would give you a link. Go to ANSI's SAAMI listings. Or some of the newer load manuals. The case walls are thicker and the web section is larger in the 454 case.
One thing of note. I have had more case stretch in my 45 Colt cases (magnum levels) in the 1894 than any of the revolvers. My revolvers vary somewhat, but in minor way.
I keep good notes for all my loads. I shoot the same cases in the same guns. I am pretty OCD when it come to loading. The FA does very well in low case stretch(tight tolerances). The Colts do too, but they are loaded much milder. I go by my notes, not what is posted on the Webbnet.
You know we are talking about minor differences here. But at very high pressures over and over there is a possibility of a ruptured case. The 454 cases were designed from the beginning for these pressures.
