I'd pull one of the bullets and roll it by itself. I'd bet the bullet itself is not made right or cocentric.
Everything in the reloading process is made to keep things centered, I can't see being able to seat a bullet off center, the die even without the correct seater plug will want to center it.
Check the bullets by themselves.
What kind of bullets you loading?
In Memory of Paul "Dietrich" Stines.
Dad: Say something nice to your cousin Shirley
Dietrich: For a fat girl you sure don't sweat much.
Cue sound of Head slap.
RIP Muggsy & TMan
"If you are a warrior legally authorized to carry a weapon and you step outside without that weapon, then you become a sheep, pretending that JOCKO will not come today."