I just loaded them into 38 Specials. No problem.
How do I fix the roll crimping problem?
You have to back up the die. The 357 case is longer; you have to allow for that. Your die set should have came with a spacer to use when reloading the longer 357 casings. Put that spacer between the die lock ring and the press. That is usually all you need to do...if not it is a good start.
If you are getting good results with 38 special, you are on the right track. Backing out your die will work. Also, use the spacer on all three dies. You probably will not have to redial them in...just remove the spacer when going form 357 to 38 Special.
When using lead, I always flare the mouth enough that the bullet will sit up straight when placed in the case mouth. You don't want shaved lead loading up your seater die...and as has already been suggested...I always seat and crimp in separate operations.
