flint head
I can give you my perspective on it... Tom was going to hunt with the 52 Knight this season. He and I were discussing it on the phone one evening and came up with the thought that it would be nice to have a 220-250 type bullet in .458 to shoot from the the 52 or even a 50. Next I believe Tom talked to Dave about it, he did some math and came up with the .458/220 gr.
Tom got them and gave them a workout - they turned out to be really accurate and I believe Tom did harvest more than one deer with them.
I think... Dave has not put them on the web sight yet as they are a bullet in development.
I have shot them from both my 52 and 50 (testing) - they really should be an excellent whitetail bullet.
That is my 2 cents