Down loading the 458WM to 45-70??

[Rafiki]

Recoil energy is a function of the mass of the bullet, powder and fiream, and the velocity of the bullet and powder. Try a 300gr whatever pushed to 47-70 velocities (~1500fps) using A5744. Using A5744 you do not have to be (too) concerned with load density. I assume the 458WM is a somewhat heavy rifle that would dampen recoil some. 12ga slugs are notorious for being thumpers on both ends.

It really sounds like a situation you may want to think twice about but if you decide this is what you really want to do plenty of range time is needed. She needs to become very comfortable with whatever you come up with before you stick her up in a tree; the bear would appreciate that.

 

[Ontario Hunter]

Shoot slugs out of that 11-87 auto shotgun. The recoil will be quite manageable ... because it's a gas auto with some weight to it. Cut it down for her if needed. Lots of aftermarket stock options for that gun. You can always buy a used stock on eBay, cut it down, and toss it after the trip.

 

[Ridge Runner]

Thanks everyone for the help.

I did a test with a few rounds with variations weights of IMR 4064, 47.2 to 50.2 grains, using 350 grain jacketed soft point 45-70 bullets. I think 52.0 grains of IMR 4064 would be the best load. Reason being the test loads ranged from 1430 to 1512 fps. The felt recoil was comparable to a bit heavier than a 28 gauge shotgun.

I quit testing because she ended up liking the 45-70 guide gun she fired at the range, thus no need for further testing.

Unfortunately for her there wasn't enough range time to work with her shouldering technic before her bear hunt. She places the butt to low on her shoulder creating excess elevation much like a beginner left eye dominant shooter shooting a right hand rifle. She can hit the target but her hits are not as tight or consistent as they should be.

As for the bear hunt it was somewhat successful my nephew and 2 other members of their group ended up getting some nice bears. My niece-in- law and a fifth member saw bears but weren't able to get any shots off.