yes it does refer the 450 rimless but however my preference for lion would be the 416 Rigby in a bolt action or a 470 nitro express in a double rifle. I would prefer to use the double rifle as you would get two shots.
Hi Kenneth McMillan,
The .416 Rigby was not mentioned in your original post/question but, it also enjoys an awesome reputation on lion, by means of the Rigby designed 410 grain Round Nose Soft Point, beginning well before WW-I (introduced in 1911 I think).
John "Pondoro" Taylor spoke very highly of the .416, describing it as the very best caliber for stopping a lion's charge.
You mentioned Nosler Partitions in .375 so, it is worth saying that the NP is also available in .416 diameter (400 grain) and I will guess most PH's would happily guide you to a lion with such a combination.
Woodleigh makes the 410 gr RNSP if you wanted to be totally nostalgic (I have that tendency most of the time).
Be all of that that as it may, according to his own words, Taylor mostly used a Farquarson single shot in .375 H&H with 300 grain RNSP for lion.
As he put it; "with plenty of lead exposed at the front" (or words to that affect).
Since it was chambered in a single shot of those times, I presume it was the "flanged" version AKA: rimmed version.
The flanged ammunition with 300 gr bullets was loaded to "only" 2400 fps, for use in doubles (weaker breach than the Mauser).
Coincidentally, that is my favorite load in bolt action .375s as well, for hunting in conditions typical to most of Africa, what we would call "woods hunting conditions" or "brush hunting conditions", here in N. America.
Once I did own a double in .375 H&H (rimless-belted) by Merkel and paid Champlin Arms to re-regulate it to that load as well.
With same I hunted in Africa for my 2nd safari, taking 9 animals.
It was a plains game only hunt but I felt confident that if some grumpy lion tried to clobber me or anyone present that, I was not under-gunned at all.
As for using a .470 double on lion, I do not need to say it is plenty of gun.
There is just something about stalking game at close range while carrying a classic double rifle.
I sacked the buffalo in my avatar with an English double in .450No2 Nitro and I would not trade that memory for anything.
However, for my safari dollar (if I could afford a lion in the first place and if a frog had wings), personally I would likely choose a Mauser that I already own.
It's a Brno 602 magnum in .375 H&H, with 4x Zeiss scope in Alaska lever rings / open express sights as my backup plan, large white front bead, wide shallow V rear sight.
Blah, blah, blah,
(Help, I'm typing and I can't stop).
Velo Dog.