We have not changed the law--there is no minimum caliber as long as you are NOT using a rimfire weapon. (See muzzleloading equipment exception below).
In any hunt, including any-weapon seasons, it is unlawful to pursue or kill big game animals:
• By any means other than approved firearms, muzzleloaders and archery methods.
• With any electronic device attached to, or incorporated on, the firearm or scope; except scopes containing battery powered or tritium lighted reticles are allowed.
• With any firearm that, in combination with a scope, sling and/or any attachments, weighs more than 16 pounds.
• With any fully automatic firearm.
• With any shotgun using shot smaller than #00 buck.
• With any rimfire rifle, rimfire handgun, or muzzle-loading handgun, except for mountain lions or legally-trapped gray wolves.
PLEASE NOTE THE RESTRICTION BELOW WHEN USING MUZZLELOADING EQUIPMENT:
Muzzleloader Caliber Requirements
In any hunt, including general any-weapon seasons and shortrange hunts, it is unlawful to pursue or kill big game animals with any muzzleloading rifle or musket that is less than .45 caliber for deer, pronghorn, mountain lion or gray wolf; or is less than .50 caliber for elk, moose, bighorn sheep, mountain goat or black bear.