metal prepping was done in my blasting cabinet using 120 grit aluminum oxide as per recomended at Lauers website. on the muzzel end i used play dough to protect the rifling. whatever you use to blast with make sure you use a good breathing respirator to keep it out of your lungs. next up is my Ruger single six after i reline the barrel.HTH. one more thing what grit is that aluminum oxide you got from harbor freight? also the 10/22 reciever is aluminum so don't worry about the 120 grit oxide doing damage to it.
Rick