my favorite handgun for bear is an remington 870 marine magnum 12ga loaded with copper slugs....

yeah, i know but if i had a grizzly problem, a handgun just doesnt seem like enough.....

This is about as good as it gets for 44 mag ammo for bears. It may not be suitable for some revolvers so check out the warnings. If you have a Ruger you should be fine.
Garrett Cartridges Inc.

No bullets , slugs are approved.

Originally Posted by rgrundy

This is about as good as it gets for 44 mag ammo for bears. It may not be suitable for some revolvers so check out the warnings. If you have a Ruger you should be fine.
Garrett Cartridges Inc.

Garrett is probably the most "outspoken" of the weighty hard-cast lead bullet at high velocity community. Nothing wrong with that.
His short exposition on the why and how of hard-cast bullet performance is well worth reading.
Garrett Cartridges - Defensive Shooting Of Bears With The Revolver

Two other sources of the "hard-cast" and "hot" ammo variety are Grizzly and Buffalo Bore. You can check various loads and data at Midway USA.
Ammunition - Shop Premium & Discount Ammunition at MidwayUSA

My hiking carry gun is a Ruger Super Redhawk Alaskan (2 1/2" barrel snubby) in .454 Casull.
I prefer an expanding hunting bullet for "soft" lions. And Blacks are not as tough as Grizzlies.
I use a Win 260 grain "Partition Gold" Nosler bullet at 1800 fps muzzle velocity yielding 1870 ft-lbs of energy in a 7 1/2" barreled gun.
But, my snubby barrel probably reduces it's actual performance to that of a hot .44 Mag load.

As always, YMMV.