I'm a one bullet guy for all except my 6.5x55. I bounce back and forth between 129gr bullet's and 140gr! I have believed for years that caliber is not so important as bullet. Use a bullet that that will hold together and destroy vital parts and the animal will die, simple as that! Use a bullet that will penetrate the neck and break the spine and the animal is going right down, easy! Shoot an animal with a 22 LR where the bullet will reach the brain and the Animal is dead. Caliber make's little difference, use what you have right and you will kill animals. Someone mentioned his brother using a 165gr bullet in a 300 mag and killed everything. No surprise, the guy knew how to use it. The advantage to the magnum's is mostly the ability to handle heavier bullet's better. A 30-06 will handle a bullet just fine but a 300 mag will handle it better! The same bullet at a better velocity won't kill any better but will penetrate better and shoot flatter.
How you set up the rifle you have seem's to be the major point. If you find the heaviest bullet for your cartridge it will shoot fairly fast and flat, it will penetrate. No need for a premium bullet. On the other hand a monolithic bullet retains most all it's weight, give it a penetration advantage over a heavier bullet that doesn't retain as much weight or reach the same velocity. In each bullet, the secrete to success is getting a bullet inside that penetrate's deep enough to destroy vital organs. Get a rifle in a cartridge that recoil doesn't bother you, chose a bullet that pretty much does all you want and learn to use it.
If you are getting reduced recoil loads, you have a rifle/cartridge with recoil you can't handle. Reduced loads will lower velocity, that's how they reduce recoil!Drop down to a cartridge you don't need reduced recoil loads for. I think it's silly to brag about your 300 mag if your using reduced loads ad in fact falling below a 30-06 or even a 308. Then what's the point of the 300 mag? The 30-06 is probably the best all around cartridge but claiming that is pretty much splitting hairs these days. Not a lot you can kill these days with a 300 mag you ca't kill equally dead with say a 6.5 Creedmoor! Just depends on how you use what you have!
Lot of people claim they eed a rifle that will reach out to 500yds. I believe that the vast majority of those people don't have the talent to shoot that far! But sure does sound good does't it? I hate reading about the guy that had to take the 800yd shot or the 500yd shot the last minute's of the season. There is never a shot you have to take unless you are under attack!
Never had a one rifle to do it all but have had a number that would have had I wanted. Have had several magnums, never own another one though. I could handle the recoil in them but only by shooting them very often! I could handle everything else with far less range time and do the same job and any range I was likely to shoot!