I have done it both ways, currently seat and crimp in the same operation. I've been shooting the "Skeeter Skelton load" for the past 25 + years, a 200gr. RNFP bullet over 7.5gr. of Unique.
I believe Skeeter's load was 7.5 gr. Unique under a 250 gr. Keith. I used to shoot a lot of that one.
