crimp will NOT secure a bullet
Bullets rely on case neck tension to secure them; crimps on 'revolver' cartridges (best = Redding Profile Crimp Die) can aid in the release timing of the bullet, but will not secure it.
In autoloading cartridges crimp removes the flare, and case neck tension secures the bullet.
I found that the surest method of PREVENTING setback is to use a powder charge that does not allow room for the bullet to be pushed back.
Not guessing about this; I've crimped the tops off of bullets (and I have some 357 Maximum cartridges someone sent me; mechanical removal of bullet required-- musta been glued in; absolutely unreal)........modifying the amount of crimp is my recommended final tweaking of already-successful ammo.
"Crimp; the Final Frontier"
Most highly recommend seating with one die and crimping with another......
"all my ammo is mostly retired factory ammo"