Picked up(locally) yesterday a 4053 with one clip. That brings my 4013 clips to 12. 6 of them I'll leave intact and 6 will be converted to 10mm. A while back I got a 4013 barrel and 10mm reamer. I'll leave the gun's barrel intact and ream the purchased barrel. I'll order springs and buffer for the 10mm conversion and then still be able to convert the pistol back to 40.