Im on this road myself. I like the 30-30 for a general purpose walk around and vehicle gun, but the regular 150 gr loads arent nice to my bad shoulder with the standard stock and hard butt plate. I may try a soft pad, and have some 130 gr Speer bullets to try. A friend has shot some game with them and likes how they perform.
Im embarking on the 243 path also, I have an older Ruger 77 tang safety in 243. We shall see how it is on my shoulder, the better stock configuration and soft pad may be enough to make it workable for me.
Part of my general purpose rifle plan includes some exploring about in the Cal desert at some point, its not an over riding concern, but its background noise.
Im pretty certain 243 and the other rounds mentioned are all decisively better game rounds for anything above coyote size than the 223/5.56. The guys that have truly accurate rifles (not me) seem to be shooting prairie dog size stuff at 600+ yards with the 243, and shoot them out to 1000+ yards with decent results. I like the idea of a 223 bolt gun for fun and practice shooting, and the relatively cheap ammo, but have little interest in ARs at this point.
I dont know how accurate the information is here, its been interesting looking it over. My previous liking of heavy 45-70 loads, 348, 338, has me now looking at rebarreling my 338 to 25-06, that may be about my top end ability now, and probably with not much shooting, just as a hunting round.
https://chuckhawks.com/recoil_table.htm