I don't have much to add that hasn't been said already, other than a word on "flat-shooting".
A lot of the new cartridges that are described as long range, flat shooting, having high bc bullets (Creedmoors, PRCs, I'm looking at you) only achieve those characteristics over older, similar cartridges at ranges exceeding about 500 yards. At the ranges most of us shoot at game (OP included as I understood it) velocity beats high BC in terms of flattening your trajectory. Mark of Mark & Sam After Work talks about this; his channel is mostly extreme long range target shooting, like 3000 yards with a .308, but he is an advocate of keeping hunting distances to 600 yards or below.
What this means is my recommendation for the OP would be an older, more common, more affordable, and faster cartridge than the newfangled stuff. Like the .243 Win if low recoil is a priority, or a 7mm Rem Mag if somewhat bigger bullets seem more attractive.
Not hating on the newer cartridges, they do what they are supposed to do, it's just easy to be mislead by flashy advertising. I just bought my first 6.5CM, and after owning a 6.5-300 Wby the ballistics at my actual hunting ranges look pretty sad. But it's a lot better on gas and doesn't cause me to wet myself at the range.
Like the fella said, "You can't have everything; where would you put it?"
Great last quote
high bc bullets the real benefits as I see them are fighting the wind, drop is the easiest thing to get right with a rangefinder and a data set for your load, the harder thing to read is wind as that's on you not computers doing basic math, so high bc is a variable that can make or break an average or below average wind reader on kill shots, put the odds in your favour, and readily available modern cartridges are available that will take over the shelves for next 100 years are where I'd recommend any new hunter or shooter go if they plan on using rangefinders and want one day to be 600 yard capable, the 6.5cm is tough to beat for off the shelf recommendation
the second best 2nd benefit to high bc is you get high sd, which means adequate penetration for the typical game animals we hunt, regardless of construction, match construction included, and it turns out for those that prefer things dying where they can see them die that match bullets with adequate sd are the sh1t, I can give my own experience there by doing majority of work with .270 win/wsm and 140 accubonds, knowing what I know now I wish I was running ballistic tips instead, as my kids came along I jumped on the 6.5 Grendel train as soon as they were available here in 2017, factory slow 123gr eldm match bullets, over 7 seasons and 21 animals with those and 7 species in Alberta our average recovery distance is like 10-11 yards, so many drt's, the odd 50 yard recovery, and a few 15 yard recoveries...bit of an extreme example but most things with the 140 ab's burning double the powder the drt was rare and the runners more like 100 yards, pretty extreme example I've witnessed in my own processing info to my own conclusions and applying in the field, I know a spectrum and I prefer a much different formula than I started with in this game
there's another factor that aids in killing things while they are in sight still, first obviously is keeping it in sight, that means recoil #1 and the other is stock design with your shooting position behind gun to aid in straight back recoil pulse, both to help you watch it happen in scope, most people have no idea that's a thing at this point as they are generally shooting way too much hp that catching it in the scope and or keeping it in the scope is off the table, they've never experienced it, the best rigs now the reticle doesn't even come off the animal at the shot let alone off the entire fov, a 3rd factor to this is magnification range for your rifle system that allows you to watch it happen so some choices will allow you to be higher in mag and still be in the scope through the whole event, and ability to correct or send more lead into it to anchor it where it is...despite a 1st shot already through the good stuff, sort of a new development in understanding, there is other benefit to this ability in if you have more than one tag in your pocket, you could fill your whitetail tags all at once for example, there's only upsides to killing and recovery with this capability
the extended long range guys that were running custom hotrod magnums with super heavy for cal bullets are figuring it out, now they are trending away from the big custom magnums now even those guys are heading towards 6mm hotrods with 115 nose-ringed dtacs etc. as they see the benefits of being able to watch everything and correct and send more, which kids and I have done with 6.5 grendels on filling a couple tags at same time with one gun across a valley between two different shooters etc., the grendel is low pressure and quiet enough this is possible here, in the usa they use suppressors to get that effect of game not hearing enough at distances to run etc. but suppressors also aid in recoil reduction or stretching the pulse out so it's easier to see I scope, ie; 308 in sporter weight without suppressor you don't see it happen, with suppressor they do see it happen
it's not always over at the 1st shot, live animals, live trigger pullers, so it's being realized it's a thing to dead is dead but the difference being dead right there or dead over the backside of the ridge and down the valley aways
