I agree
Velo Dog.
Many heavy for the cartridge round nosed cup and core bullets work great.
But when people try to use them at high speeds, specially for a magnum cartridge, you will get results you don't want.
Usually people buy a magnum because they want high speeds and flat shooting.
I highly recommend premium bullets in a 300 mag.
My favorite is a 165 or a 180 grain Barnes TTSX in a 300 mag of any kind.
My friend uses 150 grain Swift Scirocco 2 in his 300 WSM and is very happy with that on everything that moves here in Norway, including Moose.
Many years ago I tracked a wounded Moose bull for 3 days with my tracking dog.
The hunter had used a 375 H&H and he was sure he put the bullet on the shoulder.
After many hours of tracking the first day, I was sure he had to be totally wrong about where he put the bullet, but found out that he was right when I finally caught up with the bull and killed it the third day.
The problem was that the hunter had used a light and soft cup and core bullet because he thought anything would work in his "Elephant cannon" as he "only" was going to shoot Moose with it.
The bullet had "exploded" on the ridge of the scapula and not even penetrated one lung.
He started to use Swift A-frame after that and had no more problems with penetration
