I've got a .411JDJ which is a full length .444Marlin necked to .41. I usually shoot 250g-285g .411-.412 handgun bullets from CPBT or Beartooth but I have shot .416 300g and 350g Barnes xs'. By far I like the 250s bettter. The big stuff is just to much in a 12 inch handgun even a scoped Contender. BTY I also have a Reeder .41GNR and a .41GNR#2 (necked .44RemMag and .445Super respectively) shoot 250g hard cast in both at about 1150-1250fps nice and easy on the hand and wrist.