No offense to you or your brother but that advice regarding only pistol bullets doesn’t really tell the story regarding 444 Marlin performance. True there are 44 Mag designed bullets that shoot well in the 444 Marlin, many discount their effects, but a 225-250 JHP at 2,400 fps-2,500 fps dumps massive expansion, energy and wounding on big bodied animals in the 400 lbs class. That is only the beginning as there are many .430” JFP bullets from 265 gr- 300 gr made by Sierra, Speer, Hornady and Woodleigh. Barnes makes a solid FP 300 gr bullet (Buster), which is a bone crusher that I load at 2,000 fps. Then there are 20+ Keith style HC bullets from 200 gr - 400 gr. I load 290 gr and 335 gr. I still have 50 rounds of the old 280 gr CorBon FPX that clocks at 2,250 fps. Have killed two elk with that load and it was impressive. Many comment on not having the power for big bears, I for one would not hesitate to shoot that 280 gr CorBon load on a big bear and back it up with the 300 grain Barnes Solid at 2,000 fps or the RimRock 335 HC at 2,100 fps. No bear is going to survive the penetration and wounding of well placed hits from those big projectiles out of a fast handling lever gun under field hunting conditions. I always have to chuckle when the 444 Marlin is demoted to some lowly platform from many who have never loaded for it and can’t appreciate the various levels of performance it can be dialed in for. Like always the only thing that matters in bullet performance is matching the bullet to the intended game and the 444 Marlin does that very well. Best Wishes.
