I have an original pre-war Model 71 in .450 Fuller. This is basically the same as a 450 Alaskan but with less angle at the shoulder.
This one came from JKR-Rifles-Harold Johnson's Shop-
Ackleys Vol I mentions this cartridge-He actually preferred the original to his as it was more reliable in feeding. The Fuller was named for Johnson's gunsmith who made the reamers-with an 1886-it was even more reliable as the 1886 had a more reliable shell carrier
that adapted to cartridge length. If anyone has
a Fuller or older Alaskan-would like to hear from you.

I have used Hawk and Alaska Bullet Works-Juneau
bullets as they hold together well.
Also have a 348 Ackley Imp that has been used successfully in the Alaskan interior on moose.
It truly is the equivalent of a lever-actioned .35 Whelen with 270 gr Hawk bullets.

The 1886/M-71 rifles are still favored by guides and hunters in Alaska and Canada because they can be reloaded through the side loading gate-while cocked with a round in the chamber!
It is really handy with a wounded brown bear or grizzly-

LTC Ridge M