It's hard for any new cartridge to crack that line-up, because the standards and semi-standards work for 99% of hunting anywhere on earth. While rifle loonies can (and do) argue that their particular favorite is "better" than an old standard, the differences are so minor (especially for the average hunters and shooters who buy the vast majority of factory rifles) that they're meaningless in the field.
Factories keep trying new rounds, though, in the hopes that they'll become the new standards. At the very least they'll sell some new rifles to loonies, and once in a while they win the lottery. Since 1950 Remington won with the .223, .22-250 and 7mm Magnum, and Winchester with the .243, .308 and .300 Magnum.
I guess my point was more to the fact that some of our now medium popular cartridges didn't start off very well and would have been starved into obsolescence by their manufacturer in today's market.
For example, the .338 Win Mag or .280 Remington.
Obviously, the world could probably do without either, but if that is the measuring stick, then most could go.
It just seems to me like some cartridges don't hit their peak popularity until several years or even decades after introduction and killing them soon after their release makes that an impossibility.
