I have the 1st 9.53 (375-cal) Hellcat Lazzeroni made and it's a great round --- matches and exceeds normal 375 H&H ballistics in a .308 length case.
The Maverick is the same case necked up to .416 and I don't know if it will get 2400fps with the 400gr bullet or not --- probably fairly close.
I know John has messed around with the larger ones but I think there was trouble getting them to headspace properly.... the abbreviations are --- Big Bad Mother xxxx and Little Mother xxxx each based on a different size case.
I've been on my last safari and my Hellcat is for sale. 300gr Nosler Partition at 2550+ fps well under moa for 3 shots.
