The James H. Watts copyright of 1952 for the ".450 Watts Rimmed" appears under the heading
COPYRIGHT OF THE .450 ALASKAN CARTRIDGE
on page 73 of this book by Cal Pappas:
That account leads one to believe that Watts was in Washington state during 1950 to 1951,
teaching at a University in Seattle and having Harvey Anderson in Yakima, WA build his .450 Watts Rimmed
1886 and M71 rifles for him.
He went back to Alaska and built bridges on the Seward highway and as far west on the Kenai Peninsula as Cooper Landing,
where Watts showed his .450 Watts Rimmed to Harold Johnson in 1951.
Johnson adopted his version of it as the .450 Alaskan, and the rest is history, fascinating.
First .450 Watts Magnum on an FN Mauser in 1949, copyrighted in 1950 by gunsmith Harvey Anderson.
First .450 Watts Rimmed on a re-bored (by P.O. Ackley) .40-65 Winchester 1886 that had belonged to Mrs. Watts Grandfather,
chambered by Harvey Anderson,
second one done by a re-barrel of a new M71 .348 WCF, all circa 1950 to 1951, copyrighted in 1952 by James H. Watts,
probably after Harold Johnson started making them as the .450 Alaskan in 1952.
James Watts is the Rodney Dangerfield of the .450 Bore.
His pets in the H&H belted case included brass lengths of 2.00, 2.25, 2.50, and 2.85 inches.
Winchester liked the 2.5" case best.
James Watts killed a grizzly charging him in the middle of Black Rapids Creek,
with one shot from a .375 H&H M70 in 1938.
But the bear came on and smacked Watts' gunbelt off his waist with a paw as it ran over him.
That was the inspiration for the .450 Watts Magnum finally realized post WWII in 1949.
It occurred on a solo 400-mile walk from the Fairbanks area to Valdez.
I once drove it with the inlaws in the back seat of my SUV.
That was a test of endurance also.