I roll 420gr hard cast @ 1700FPS in my GG. I could go to max book for a GG which is ~1800fps, but I'm not sure why I would. I keep my GG around for grizz protection if we have game down and a camp gun. It's not my favorite gun to shoot with those loads, recoil is stout. I have some 300 gr cast plinkers I load to ~1800 fps, those are a lot more fun to shoot.

"Life is tough, even tougher if your stupid"
John Wayne