That's a great activity for you and your grandson papadave! I hope it turns out terrific for both.
I really need a shootin' buddy myself. I have three grandson's, 7, 4 & 3 yr. olds. I've been drawing a bead on my 7yr. old to take him shootin' with me when he gets a little bit older.
I've even been thinking of buying him a BB gun to learn on, with me, in the backyard before I take him out for real shootin'.