Polymer and lightly plated bullets may want slightly less crimp but the technique is identical.
Most cast lead and coated bullets have a crimp groove.
Crimp into it. They are usually deeper than a cannelure.
You don't need to get all the way to the bottom.
I did a small test with my first polymer bullets to see the damage, if any, from pulling the bullets back out.
A good coating is bonded to the lead and won't be damaged much.
As you can see from the picture there is very little difference in damage from a profile (Redding roll) crimp and a taper crimp.
Neither is going to affect anything.
Lead and coated bullets have lower friction than jacketed and consequently go faster with a given load.
Plated bullets, oddly enough, have the most friction of all.
I have a theory about that I'll explain maybe later if asked.
Adjust your powder load accordingly.
Plated bullets are usually loaded as if jacketed but kept sub-sonic.
The Lyman manual is considered the "bible" of cast bullet loading and has thousands of loads.
There are 2 books.
One is just for cast and the other, newer, one is an over all manual.
The 50th anniversary book is a good start.
