Hello, had the same problem with a Blackhawk convertible that a friend of mine owned that never had a problem with it. He shot only 230gr RN reloads and used a Lee Factory crimp die.
I on the other hand primarily shoot 200gr SWC in plated or coated. If I remember correctly I had the issue with the coated bullets. Do you have a case checker that you can also check your reloads in jus to see that they conform to those standards?
Also you may try a Lee Factory Crimp die on the ones that did not fit and see if that helps. And of course you are doing a taper crimp I assume.
Karl