camper mirror nuts

[dads longhorn]

Ive noticed that some pictures on here of camper mirrors (the big rectangle ones) show nuts that are bullet shaped. and when i got a set from someone on here months ago, they came with bullet head nuts. I like them, much cooler than regular hexagonal nuts. I think the only place on the mirror they are used is to hold the mirror to the support. does anyone know if the bullet heads are the originals? are they only used in that one place on the mirrors? also, since the bulletheads are dead end nuts, i may have to use washers to take up slack when tightening??? Thank you in advance.