RE: low hunting calibers?
I like my 7-08. First one was a model 7 rem. I got rid of that gun fairly quickly for one reason.....the barrel was 20 in. The muzzle jump and muzzle blast was steep. It is amazing what 2 more in of barrel and a little heavier gun will do. I settled on a browning a bolt in 7-08. Have shot numerous deer with it. Even took it elk hunting with 160 grain nosler partitions, though I did not shoot an elk.
The 7-08 allows you to use some pretty nice bullets in the 140 grain range that are store bought. You can also look up conley precision ammunition for some custom loads. I have been shooting the 154 gr hornady round nose on hogs recently.... good medicine.
I also think the 260 would be superior to the 243 and 30-30, as is the 7-08. There is not a deer out there that these two rounds wont dispose of inside 250 yards, with a well placed shot.