I just loaded some I found I had setting in a baggy that I picked up long ago at a gunshow. I just finished off my supply of cast 124-grain 9MM bullets, and I reached for the plated RN bullets I have. The lot I have are slightly under 124-grains.
I am using a 4-die carbide die set that creates a factory taper crimp, not a roll crimp. I seated bullets in two resized, unprimed cases, and then used by hammer type bullet puller to remove the bullets.
1. Bullet tension is good and I have no concerned about the bullet being retained in the case if dropped or under the force of recoil.
2. The taper crimp leaves a very shallow line in the copper platting.
3. I used the same data I was using for 124-grain lead bullets.
The 9MM headspaces on the lip of the case and I go for more a tight fit than a true crimp. The practice rounds feed without a problem in my pistol.