How many times have you read a poster say "I never trim my pistol brass".
Lee 4 die sets have a factory crimp die with a carbide ring in the base of the die. This is a "cheat" for people who do not trim the cases to one OAL and get a uniform crimp. The carbide ring in the base of the Lee crimping die will size any bulge below the crimp on the longer cases.
Bottom line, your not reloading for a scoped rifle cartridge and trying to load the most concentric cases you can make. And at normal pistol ranges a Lee carbide 4 die set will be fine.
That being said I have a Redding carbide die for my .44 magnum because it has the same type expander as the Lyman type "M" expander. And this greatly helps in straight inline seating of the bullet. And I have bought Lyman type "M" expanders for all my older dies.
Below is a newer Redding pistol die, and the center die is the type "M" expander. This allows the bullet to start straight into the case and prevents the bullet from tipping during seating
NOTE, I'm 67 and have chronologically gifted eyesight and drink too much coffee. And many of you younger pistol hoo .
Below is a photo of the Lyman type expander for a .223, as you can see the upper step of the expander is larger than bullet diameter. This does not flare or bell the case mouth and over expand the case mouth. Meaning less split case mouths from over working the case mouth and more uniform concentric bullet seating.
NOTE, I'm 67 and have chronologically gifted eyesight and drink too much coffee. And many of you younger pistol hoo
Below I only bump the case onto the second step "B" below and never flare the case mouth like "C". Even with brass spring back the second step is slightly larger than bullet diameter and the bullet can be pushed in by hand.