: Marlin 1895
: 22 inches
: 1:20 inches
: 24 X
: 50 yards
Click on figure to access ANSI
technical cartridge drawing
A wildcat cartridge. Developed by Harold Johnson of Cooper Landing Alaska, ca. 1952 (predates 458 Win Mag by 4 years). An artifact of watching a much too close brown bear suck up multiple 30-06 shots and then moving on. Based on a 348 Win case being necked up to accept a .458" bullet. One of three major such wildcats.
When introduced in Jan 1936, the 348 Win was this countries most powerful lever gun cartridge - the kinetic energy of a 30-06 in a .348" brush busting bullet. The 348 in the then also introduced Win m71 lever gun proved a successful combination, many large game animals were taken - elk, moose, bear etc. Unfortunately, in Alaska, where all the critters are larger, too many hunters were dropping (charging) animals much too close to their feet and too many rounds later.
The m71 is a modern lever gun, it is strong - but it still isn't a bolt gun, pressures must be kept moderate (Win limits the m71 in 348 to 44k PSI). A 348 Win with its .348" is a 2900-3000 fp cartridge. By increasing the bullet diameter to .458" (and hence mass), and still loading only to 44k, one generates a 4200 fp cartridge. This is what Johnson did; likewise Ackley and later Fuller.
The 450 Alaskan is a 348 case, blown out, retaining a moderate .028' body taper, necked up to .458", keeping a .035" ghost shoulder. The resulting case capacity is slightly greater than the 458 Win Mag. (The Ackley version, the 450-348 Improved, trims the body taper to .010" and uses the standard Improved 40 degree shoulder; the 450 Fuller version adds .004" more body taper back in and reduces the shoulder to 20 degrees. Because of the more tapered nature, the 450 Alaskan feeds better than either of these other variations.) Case capacity for the 450 is, full case, 88.1 gr. (of water), with a bullet seated .400", 71.4 gr. In comparison, the 458 Win Mag offers 87.4 and 70.8 gr., respectively.
When chambered in a 9 or 10 pound gun, the recoil from the 458 Win Mag is "noticeable". The m71 is a 6.5 pound gun. The recoil from the 450 is "more than noticeable", some might label it severe.
At 4200 fp muzzle energy, the 450 Alaskan is viable on all North American game.
Nominal bullet diameter is .458". Both case forming and reloading dies are available from RCBS.