I developed an accurate load for my 260 tactical magazine fed bolt gun using Sierra 142s with a compressed load. I am using a Redding bushing die with a bushing .003 smaller than a loaded round. As a result using a Wilson seating die I am getting a ring mark on the bullet while seating. The ring mark on the bullet has not affected accuracy and it actually comes off with a little steel wool. The ring mark doesn't happen until I start to hear a little powder crunch. My idea was to pre crunch the powder using a 6mm expander mandrel. Has anyone out there tried this? And yes I am super fussy about my reloading. I want my ammo to look as good as it shoots. Thanks, Ray