Yeah, Bill, the High Power would be more "correct," but I think his premise (from the other posting) was that his protagonist lived or was stationed in the US in 1913, and became "enamored" with both America and the "Old West," and Colt Firearms in particular, where he bought the "co star," his pistol...
Using the .45 auto came about when Wolery was informed the Colt Single Action Army couldn't take "speedloaders," even though I STILL think he could make THAT work even without them with a little "literary license..."
SLOW methodical .45 Long Colt 255 grain pills taking out the Germans "spraying and praying" ineffectually with their Schmeisers...Kinda like an old "McCloud" episode....
Plus he could intersperse the occasional "fast draw" sequence he learned straight from a "B" Western or Buffalo Bill Show where our guy would leave another thoroughly surprised Gestapo Goon lying on his back with a Luger half out of his flap holster with a "third Eye..."
(GOSH I should be a screen writer...
)
The Browning High Power was not built until 1935, right?
Plus I think he originally wanted a big bore magnum for the effect, and "settled" for the .45, larger than the "puny" 9mm that would be "lost" among all the Nazis shooting back...