Per Dillon:

8.5. If there is no groove or cannelure, do not over crimp the bullet. Over crimping can damage the bullet
and reduce the “hold” on the bullet due to the bullet being deformed and the brass case springing back
away from the deformed bullet. Crimping a bullet without a crimp groove should only reduce the
diameter of the brass case mouth/outer diameter .001-.002”. A reduction of case mouth diameter
greater than .002” may cause bullet deformation and a loose bullet. Note-- it is not necessary to use
the cannelure if your COAL is not compatible with the location of the cannelure.

https://www.dilloncdn.com/manuals/dillon-die-instructions-english.pdf

I was putting a crimp on my rounds that reduced case size .005 when I check. What I learned that a .002 crimp is barely noticeable at the press handle.