RE: 444. Marlin
I've tried allot of different bullets and had the best luck with the 265Gr. Hornady flatnose. I've personally seen it take down a Buffalo at 265 yards. Not bad for a 444... That was with a max load of H335. I was able to duplicate the performance of Hornady's Light Magnum load pretty closely...
I'd show you a picture of what it did to the Buff's heart but it's kinda gross...