It depends for me.
All cast bullets:
If I'm doing 44 Specials, the die is set for the Lyman 429421. The brass is all the same length and doesn't seem to stretch, so I seat/crimp at the same time. The crimp groove in that bullet is so ridiculously large that the case mouth doesn't dig in and plow lead in the last few thousandths of seating, so it works out just fine. I don't do rompin'-stompin' loads or shoot much past 50 yards any more and minor things which don't have much effect at the shorter distances are omitted.
If I'm doing 357s with wadcutters, I seat/crimp together.
Bottle-neck rifle (30/30 single-shot, 222R bolt-action), I don't crimp at all.
357 Mags and Maxes, for the rifle, or 357 Mags for revolver AND rifle, I seat and crimp separately, especially for heavier loads. THEN, I use the LEE factory collet crimp die.
When I DO seat/crimp at the same time, I turn the seating die out just enough that it it doesn't crimp. This leaves the bullet seated long, so I adjust the seating stem until I get the seating depth I want. Then, I hold the seating stem still with one hand and turn the die body down separately. Easy on LEE dies. If a tweak is needed after turning the die body down to crimp, it's usually not enough to plow lead with the case mouth.
I prefer the collet crimp die over a roll crimp, so that dictates separate steps. I really like that die though
The only jacketed I still shoot is the 223 in a single-shot and I don't crimp that one at all.
All cast bullets:
If I'm doing 44 Specials, the die is set for the Lyman 429421. The brass is all the same length and doesn't seem to stretch, so I seat/crimp at the same time. The crimp groove in that bullet is so ridiculously large that the case mouth doesn't dig in and plow lead in the last few thousandths of seating, so it works out just fine. I don't do rompin'-stompin' loads or shoot much past 50 yards any more and minor things which don't have much effect at the shorter distances are omitted.
If I'm doing 357s with wadcutters, I seat/crimp together.
Bottle-neck rifle (30/30 single-shot, 222R bolt-action), I don't crimp at all.
357 Mags and Maxes, for the rifle, or 357 Mags for revolver AND rifle, I seat and crimp separately, especially for heavier loads. THEN, I use the LEE factory collet crimp die.
When I DO seat/crimp at the same time, I turn the seating die out just enough that it it doesn't crimp. This leaves the bullet seated long, so I adjust the seating stem until I get the seating depth I want. Then, I hold the seating stem still with one hand and turn the die body down separately. Easy on LEE dies. If a tweak is needed after turning the die body down to crimp, it's usually not enough to plow lead with the case mouth.
I prefer the collet crimp die over a roll crimp, so that dictates separate steps. I really like that die though
The only jacketed I still shoot is the 223 in a single-shot and I don't crimp that one at all.
