DL380 Gen 9 rack rail kit holes too small for threaded rack

[EWInfotech]

I have two DL380 Gen 9 2U servers and their included rack mounting kits, part number 729870-002. Our server rack is a classic threaded round hole type.

After removing the inserts as instructed in the guide, I discovered the hole on the front of the rail kit are just barely too small to hold the screws we use in our rack. The rear mount on the rail kit fits OK.

I was going to attempt to drill out the holes on the rail kit, but before going to such dramatic lengths thought I'd better check to see if maybe I have the wrong part somehow.

Here is the front bracket with the holes which are too small, as if there's some sort of insert in them:

And the rear bracket is fine:

It appears that with significant force I could split the two laminated halves of the front bracket apart and hopefully clear the holes, but I'm not sure that's going to resolve it.

Should I break out the drill, or is there some other solution I'm missing here?