If you order the Fair-Rite 2843002402 ferrite core, you may see there are two different external appearances for this product.
Both parts are okay to use. There is no PCN for the difference. As for the beveled edge, this is caused by the different tooling used to press the parts. This is not a controlled dimension and this will not affect the fit, form, or function.
Concerning the apparent difference in hole diameter, one part has a lead-in feature and one does not. If you measure the holes with a pin gage, both cores should have the same measurement.