I reload for the Model 52 and have for about 15 years. I was told the secret of the gun years ago after a struggle to get it right led me to contact a fellow at Smith who built the guns. He said the gun was based on the Model 39 which is a 9mm and to forget that it was supposedly a .38 Spl. He told me to slug the bore and if my gun had a .356 bore, sell it and look for a .355. They made both. I actually had purchased a second one at the time and it had the tighter bore. He also said to use a 9mm taper crimp and to buy HBWCs that were sized at .356. 2.7 of bullseye in a nickel Federal case and you are good to go. Mine will shoot 1.5" at 50yds all day long out of Ransom rest as long as you don't have a side wind over 10mph. If you do, leave it in the box.