There's a terrific article praising the Krag action, "A Rifle for the Poor Man," by Ned H. Roberts, from Outdoor Life 1917, reprinted in James Foral's "Gun Writers of Yesteryear." Roberts quotes Townie Whelen:
"With cartridges giving 40,000 pounds pressure and less I would rather have it (the Krag) than any action I know of. Indeed I have almost a reverence for this old-timer. It stands the racket of military service, the wilderness, and downright abuse, better than any rifle I know of."
I guess this answers the question, the max recommended chamber pressure for the 243 is 60,000 psi. I would imagine that most factory loads are
greater than 40,000 psi.
