At the risk of being redundant, 1 1/8" OD and .45" ID chambered for 45/70 would be hard to blow up.
I could do a thin wall formula for stress, and maybe a Lame's formula for thick wall, but to do it right you would need one of Roark's open end tube formulas.
So at the cave man level, I have tried to blow up many guns.
That one would be a ~~.250" thick chamber wall.
I don't care if the gun is 150 years old or new, unless it is a Ruger 454 made of specialty steel, this is my guideline:
.100" thick, I can't blow it up.
.050" thick, blowing up is easy.
The word 'forum" does not mean "not criticizing books."
"Ad hominem fallacy" is not the same as point by point criticism of books. If you bought the book, and believe it all, it may FEEL like an ad hominem attack, but you might strive to accept other points of view may exist.
Are we a nation of competing ideas, or a nation of forced conformity of thought?