Yes, I know this to be fact! The original Marlin 1895's did have a longer usable overall cartridge length than the new ones. Something changed when they put that stupid cross-bolt safety on their leverguns, and we lost a full tenth of an inch of usable overall cartridge length.
Our .45-450g LFNGC bullet was designed around the old .45-70 Marlin 1895SS pre-crossbolt safety guns. It fed perfectly in them with no alteration what-so-ever. Talk about some stopping power when that thing is wound up to 1900 fps out of the Marlin! OUCH on both ends!
If you are lucky enough to have a pre-crossbolt safety gun, then you can indeed use a longer overal cartridge length.... sorry all my data is down in the shop office, and I'll have to look up exactly what that C.O.L. is for the pre-crossbolt safety guns. I'll post it later if you're interested.
Hope this helps!
God Bless,
Marshall