357 mag. My 11 yr old shoots 38 Sp in his, for practice. No recoil, cheap (especially with my reloads), and every store that sells ammo has 38's if I run low on the reloading chores. The long throated Handi lets me load 360 DW for his deer hunting. The 180 gr. Hornady SSP shoots accurately in the DW, with enough oomph for a 100-125 yd shot on Bambi. He gets to shoot it enough to get accurate and comfortable with it. It has worked out great for us.