bearings and ballscrew dont fit each other

[Gary]

Cheap verniers are renowned to be inaccurate.

[JAZZCNC]

Defiantly will be the measuring. You can not accurately measure internal dimensions using verniers, you can't really accurately measure the shaft with verniers you need micrometers for both.

But like Jonathan says your using the wrong bearings any way so do your self a favour and get the right ones. They still won't fit if shaft dimensions are off but they will be correct for when they do.!