I own a 300 RUM and love the caliber as well. It is as capable as any caliber has to be and my sendero is extremely accurate with is caliber. It does have it's drawbacks though. To get that performance is not cheap. The shooter has to get past the recoil, the cost and availability of ammo, and the decrease in barrel life. I love it and it's performance is hard to beat but I can't call it the best caliber because of the points I mentioned and others that I am sure will be mentioned. I hope you have your flak vest on.

The 300 RUM is probably the odds-on choice among the 300 Magnums more potent than the 300 Winchester Magnum. It is more practical and efficient than the 30-378 Weatherby Magnum. It can't kill anything the 300 Winchester Magnum can't, but it shoots faster and flatter.

The 7mm RUM is not as good, in my opinion. Case efficiency for this cartridge is a big problem. The 7mm STW and 7mm Weatherby Magnum are more efficient, and just as potent. The 7mm Remington Magnum can be loaded to achieve similar performance without the risk for popped primers or excessive case loss.