Ya if you look they are listed as 416 Taylor but the product specs list 6.5x300 weatherby
I suspect the Amazon vendor has had just an ignorant mix up by the listing company.
Regarding your original query, the .416 Taylor is a nice balance of power/bullet weight, velocity in a standard size (your Ruger 77MKII) action, or a Model 70/ M98 standard magnum action
I've owned a 416 Taylor, built on a commercial M98 Mauser action with all the proper metal work.
NECG banded front sight, barrel band sling swivel, NECG V adjustable rear sight, 3 position safety, Cerakoted metal, in a Bell/Carlson synthetic stock, 22" barrel.
I bought it many years ago, all set up.
That was the most
shootable big bore (really large medium bore) rifle I've owned.
Compared to a M70 416 Remington Safari Express, CZ 550 416 Rigby, and Ruger RSM 416 Rigby, hands down the 416 Taylor was the most "shootable" of all three.
At that time, I was buying, shooting, and then selling many different big bores.
Like a damn fool, I sold it, with dies, Lee Factory Crimp Dies, reformed brass, some bullets, to buy "the next one."
I'm "on the hunt" to find a nice M70 donor action to build another 416 Taylor, but I would build on a Ruger M77 MK II, in a heartbeat at the right price.
Craig Boddington, in
Safari Rifles (First edition), wrote that the 416 Taylor is one of those "balanced" cartridges that just works, like the 30-30 Winchester and the 7x57 Mauser.
It is efficient in powder capacity, moderate recoil, and it works.
Powder selection is very important, and worth the search. Accurate 2230, H4895, and possibly Hodgon Varget are good choices.
More data on
load data dot com is worthwhile.
Lee Precision makes a Factory Crimp Die, custom order at a moderate price.
The lower powder charges (70 grains 416 Taylor vs. 77 grains 416 Remington with Varget), does make a difference in felt recoil.
Maybe your 12-year-old daughter/hunter can learn to shoot it in a few years on her first Cape Buffalo hunt!