Thread: Neck tension problem

Hi all. A month ago a full length sized a new to me but unknown batch of brass (all head stamped the same). Loaded them with a variety of powder weights to do some ld, out of which I settled on a charge and all shot fine. This week i wanted to load them all to the chosen charge weight so thought I'd neck size them, then trim, weight powder and seat. It all went pretty straightforward except the projectiles are not seating properly due to low neck tension in some, but no all the cases. Dies used are Hornsby. ANy ideas why this happen/how can I fix it please?

Appreciate the feedback guys and gals..

Cheers Jem.