Success is also up for interpretation, as the rifle discussed is noted as having been converted to 450no2NE

Without chronograph data there's no way of telling what the velocity of the regulation load is.
For one thing, we'd take FPS and from there we could get pretty close to guesstimating pressure.
From there we could compare that pressure to the service load pressure the rifle was originally designed and proofed for -- and from there have a sense of how far out of the realm of design operation it's being run at.

Furthermore, without regulation velocity, we can't *really* call this round 450no2NE
Saying that this re-chamber job is a successful conversion to 450no2NE says that one could grab factory Kynoch 480gr 450no2 Nitro Express ammunition, and run it (at 2175fps) through your rifle with no risk of injury, damage, or catastrophic failure...
and it would shoot well -- regulate at that.

Look at the rifle resting across the black target in my sig line.
Notice the two loaded rounds of ammunition, the two fired cases, and the two holes in the target?
The target was printed with that rifle.
The brass is 450no2NE brass from Bertram.
The bullets are 350gr hornady snrn, and the load is a Nitro For Black load of Varget, a fed 215 primer, and 21 grains of dacron...
...and in no way will I ever encourage anyone to consider that rifle a '450no2NE' rifle!!

It's a blackpowder express rifle, built in the early 1880's, originally chambered in a 3-1/2" BPE round that (fortunately for me here in the 21st century) can be reproduced today, only with this elegantly available brass.
My load with the NFB load including powder, dacron, and bullet nearly equals the load mass of the original BPE load.
This load has been chronographed and pressure tested.
The pressure of this load is less than the period BPE load.
My rifle remains a BPE rifle - and I'll never call it a Nitro Express rifle.
I did a boatload of homework and research before I ever stuffed this round down the bores of my rifle too, then crept up to the regulation load over a chronograph.

I illustrate this to put some meat on the table of distinction between
-successful rechamber job
and
-successful cartridge conversion job

Someone, some day, will do a web search of some combination of words or characters or numbers and end up here reading this thread.

I'm putting this into what will be an archive of discussion and reference material that will be available for anyone to find and read.

I feel it's very important to make clear these distinctions so that some soul doesn't end up thinking that what's seen above these words in this discussion thread is supporting data for the notion that 'it's safe/possible/ok/'a good idea' to convert a 45/70 Pedersoli Kodiak Express Double Rifle to 450no2NE'

I'm not convinced that it is safe/possible/ok/'a good thing' to do that or to suggest to anyone else that it is...

...and these are just my thoughts , and not necessarily worth any more than what you've paid for them.

--Tinker