my 527 is serial number 575xx and I want to know if mine is for the 22 hornet .223 bullet or the .224 bullet. I reloaded with the Hornady 35 gr vmax .224 and there is a very slight bulge in the case throat at the base of the bullet and the fired casing is sometimes hard to extract. It shoots very well with this loading of 12.5 gr lil gun. No sign of over pressure. Thanks for any help, Tom