How to rotate a bunch of parts equally?

Hello devs,

I am trying to make a bullet hell game, so I tried to make an attack where a circle of bullets come from middle and spread depending on the number of the bullet on each ring.

But when I do it the bullets spread in a weird way.

Here is the code I tried so far:

bullet.CFrame = CFrame.new(startPos) * CFrame.fromEulerAnglesXYZ(0, math.rad(360 / index), 0) -- the index is a number from 1 to 5 in this case

By the way, the bullets does move depending on the look vector

Thanks for help.