When I was a kid, the .303 was a staple for moose for sure. The occasional guy was lucky to have a 1894 .30-30. or even a Savage99 in .300S or .308W, because the Lee-Enfields were so common and a bit boring. I remember seeing my first .270W and a .300WM both M70A's, and was very impressed with the stout recoil and blast on the .300, and this would a lasting impression on me. This would be 1974circa. There was a .303 in our house, a LongBranch, didn't know what it meant at the time, but I fired humpteen Dominion 215KKSP's out of it, ammo left over from my grandmothers general store. My Grandfather had a woodWorking business, and used to by crates of No1's and No4's, bubba them and resell in the store. He told me he payed around 8 dollars each, and sold them bubba'd and zeroed (a job he gave to a local WW2 vet) for 20 dollars each. My mom just recently sent me a nose cap from a No1, found when part of the old workshop was demolished.
When I started hunting in the late 70s and into the 80's, every third rifle in the woods it seemed was a .303. A chevette or fairmont would wizz by me early in the morning and 5 kids would pile out, 2 with single shot shotguns, one with an old 94 .30-30 and two with old 303s. They'd beat the woods all day. Lots of deer back then and lots moved by those young enthusiastic hunters. Nowadays I've went consecutive seasons without even glimpsing a .303 .
Have people moved on to something bigger and better? Not really. I believe those rifles mostly found there way into the hands of the young and the more subsistence minded hunter. I was more of a pleasure hunter even as a youngster and had a new 4X4 and a scoped magnum, and all my rifles reflected this. In latter years as hunter numbers dwindled late 80s and 90s as deer herd dropped drastically here with 62,00 registered kills in 1986, and only 8999 in 1990 IIRC), those hard core sport minded hunters who stayed with it, tended to carry more modern firearms from way back anyhow. A hunting partner my age when we were both late thirties around 1997 said " when we started hunting in this area we were the kids 19-20, now I'm going on 40 and I'm still the kid in the woods, is no one new taking this up. In the very recent years I've noticed a new rejuvenation with younger hunters which I'm glad to see, but it seems most 20 odd years old today want a Marlin XL7 or a Tikka T3 or any other modern type, and the old trusted Lee-Enfields of their forefathers are not getting fielded again like traditions past. Just my observation in my local area. Anyone notice the same cycle in the past 40 odd years?