Lesson number one always buy gun stuff from a gun shop. You can't expect a person who sells toilet paper one day and ammo the next to know the answers to questions like that. I do give kudos to the walmart employees for sticking to their store policy and not trying to make up the rules as they...
Hornady new dimension dies are great. They are a true small base die which means that what you load will be safe to fire in a ar15 just as long as you set the die up to crimp.