I guess the new cases could've been too short in regards to headspace - I hardly ever use Federal factory ammo in anything so don't know what they are like in general. I was surprised at how lightly loaded they were though.

I've never checked the headspace on the rifle. I've only used factory PMC ammo through it and it was fine. My reloads are also fine and I get excellent case life (30+ reloads) with minimal case stretch and no signs of incipent head separation - the brass gets tossed when the necks split. I also reload a swag of hand me down brass in it of unknown usage history - got given to me for free. This stuff is also going well.

(Some have the headstamp "DAG" - who made this and when?)