On the Jet loading; in the Gun Digest of 1963 there is an article on reloading the 22 Jet by Kent Bella and that is where I got most of my info. He states "Factory bullets run about .2225 but I prefer .223". The rounds I have loaded in mine were .223. Also in this 63 G Digest is another Smith classic the S&W 38 Master or known now as a Model 52 this written by Gil Hebbard with another great reloading article for the 52 by Kent Bella both articles are worth the price you will have to pay for a used one on Yahoo.com, Just dont do like I did and get the 1962 G Digest with a picture of the new Model 53 Rem Jet, its only on the cover but it had a lot of interesting things.