[32-40win]

One thing you can depend on in the world of firearms and cartridges, is that the minutiae will be pounded on over and over, in the never ending quest for the elusive bughole on a target and the need to hit something on the other side of a half section, that recoils like a .22LR, and the bullet that won't deflect on a tree and go right thru it and kill what is 50 yds away, on the other side of it, but expand to the perfect mushroom and exit the critter.
And somebody will have to invent a "new" cartridge, that was made from something else, that is blown out, has a better shoulder angle for internal efficiency and will perform whatever form of magic desired by the "inventor". A great example at the moment is the Nosler lineup, they are essentially taking the belted magnums and putting them in a non-belted case, which has been done before, and probably is actually an improvement in a few ways. They just have the money to promote it better than say, the old Imperial magnum line was, which are obsolete now, for all intents and purposes.
30-30win is a pretty capable cartridge, so is a .223 Rem, 303 or a 7x or 8x57 or a 30-06 or the 300H&H or 416 Rigby or a 45-70 or a 500NE. People just need to put their own stamp on it, promote the heck out of it and themselves or their company. Look at Weatherby. And on and on and on it goes.