Do a littel research on the 450 Marlin, loads and pressures for it, and then think about the fact that NEF chambers the 450 Marlin too! There is no question in my mind that the Handi will handle class 3 loads with aplomb, it will even take a steady diet of it. For myself, I find 400 grianers ar 1400-1500 to be all the recoil I care to deal with. At 1700 fps, 400 grainers give you more than just a wake up nudge. However, if you enjoy heavy recoil and can't tell if you pulled the trigger unless you teeth rattle, then a heavily loaded handi is just up your alley