Who makes a 300gr load at 1400fps? Sounds like some serious over pressure loads.
I do.
And its more than 19 grains of h110 under a cast slug.... and its over 1400fps.... and the primers are flat... and the brass sticks..... and my RB's have eaten over 100 of them. And it would make a S&W cry. Well, shake apart, but same deal.