I hunt solo 90%+ of the time. I carried a 22 centerfire 100% of the season this year, starting with spring bears through to backpacking stone sheep trip, then Haida Gwaii, then a bull elk, then a bull moose. Predominantly a 223AI with 88 ELD m. Only variation was going to a 223 with 77TMK on whitetails, just to scratch a specific rifle itch...
Last fall I carried a 223AI, solo, on our 2 day moose season. Same as the year before. Same as this year. Killed a big tripalm/ten point in full on grizz country all on my lonesome, same as most years. 3 bull moose in 3 years, 88 ELD m, on a 2 day, highly restrictive antler tine season. Shots can be quick, at odd angles, at varying distances.
I own at least 5 or 6 (7? 10?) larger caliber rifles in "moose/elk appropriate" cartridges that are accurate, scoped, ready to go, but I'm completely confident in the effectiveness of the bullet I use to put animals on the ground faster with a 22 centerfire.
Of course, I could step up to a similar constructed bullet and run it through a larger chambered rifle, but I typically kill stuff inside 500 yards and I don't see any benefit that would outweigh the amount of meat loss that would occur, unless of course a heavier rifle that is louder, kicks harder, and burns more powder is going to bring me happiness on that particular day.
Every single time I step out the door, even walking in my driveway to get in my truck, I"m in grizzly country. A pair of sub adults licked up all the oats in my tack shed in November. That is all of 200m from my barbeque. My cartridge of choice this year was 223AI with an 88 ELDm, hunting solo. If I were of a need to kill something RFN, that was trying to bite me, based on the wound channels I have seen from 223AI-88ELDm-77TMK/243AI-105 Amax, I would pick a 22 centerfire every single time. Simply because I want the maximum amount of carnage I can inflict, and maybe, just maybe, I might get a chance at getting a second round off because its a lighter, faster rifle to handle with a shorter bolt throw and less recoil.
With a 300 Ultra or 45/70 or 300WM I'm only going to get one chance due to recoil, and I don't load those with anything that even comes close to the damage inflicted by an ELD m or TMK.
Even with a fringe hit on the edges, I have a lot more faith in a match bullet making a big football size hole in stuff and maybe touching something fatal around the edges, instead of poking a small hole in a straight line for feet of penetration, that HAS to punch something important to be effective.
One thing I have seen with my own eyes, after a couple + decades of punching mono's and bonded bullets into animals big and small, is that hard bullets kill stuff slower. Way slower.
Bullets like the Amax and ELD m, and TMK are decisively faster killers. If I'm betting my personal well being, or my kids well being on killing something as fast as possible, I damn sure am going to hedge my bets and go with what I KNOW kills stuff the fastest.
Oddly enough, I know quite a few guys that have been tagged by grizzlies to varying levels of scar tissue, and one thing they all have said, is that time slows waaaaay down when you are getting bit and clawed and slapped across the ground. 20 seconds can seem like a lifetime in that scenario, so I can't even imagine what 90 seconds would feel like when you are waiting for that hard bullet to finish what it started IF you hit organs.... Be the longest 3 minutes of the end of your life, if you just missed lung with a mono and only broke a leg bone while you waited for the bear to decide you aren't a risk anymore......