Separate Crimp Die Necessary?

When I first started reloading, some "experts" advised to seat bullet and then crimp in separate operations. Supposed to get better results somehow. Is this really beneficial?

Yes

That's what I was told years ago and have always done it that way.  I don't think the combo seat/crimp dies have enough adjustment built in to do both jobs accurately.

John

Using a separate crimp die makes both the seating depth and crimp adjustments easier.

From another Olde Pilot, I’ve always crimped separately. With soft lead bullets I convinced myself it deformed the bullets less.

Two shalt be the number of steps for seating and crimping, no more, no less. Four steps is right out. Amen
From The Book of Armaments 2, 9-21

Yes for two reasons 

1) Crimp separately does a better job at crimping 

2) If you are using different bullet types on a regular basis having a dedicated seater for each bullet type (200gn, 185gn, JHP ect.)you use makes life easier.

There is, however, one situation where a combined seat/crimp die can be useful. If you are using a 5 station progressive press and you want to have a powder check device in station 3 and a bullet dropper in station 4, then the simple solution is to have a combo seat/crimp in station 5.

This arrangement is more likely to be needed by a high volume and high power factor ammo shooter (the run & gun crowd, typically).

Only for accuracy...

Adjusting a seating and crimp die is a pain.

Separate seating die, separate crimp die. Changes to one won’t affect the other. The ease is worth the extra $30 or whatever.

Or a 7/8 washer. If you can find one.

Washer to seat. Set the stem off a dummy rd. Back it off and pull the washer to crimp.

Seat and crimp was ok for jacketed with cannelures, or cast if the crimp groove is large enough. 44 was never an issue for me.

My STAR progressives have separate seating dies and crimp dies.