Double Bass NXT-5 D'Addario Traditionals B-String through-hole size

[ArtechnikA]

Swapping out the Contemporaries that came on my NXT-5 with D-Addario Traditionals.
The ball-end silk on a few of the holes was pretty snug but the string could be pulled through without drama or trauma.
B, however, is no-go. The peg end was quite snug and none of the ball-end silk will fit.
I can measure the silk and drill the hole bigger without issue, but if there's already a "right answer" for the appropriate size, I'd be glad to know it.
If there isn't already one, I'll post my results tomorrow.
I have or can get any size needed - "English fractional," number, letter. metric - whatever.

 

[ArtechnikA]

Update:
I measured the ball-end silk at 0.205"
13/64" drill bit on hand is 0.203" - perfect.
Carefully drilled out the hole and discovered it's backed with a washer, which I should have expected...
It's way too small too.
Replaced it with a stainless 6mm flat washer from my stock.
Used a standard large 60º countersink to flare the new hole.
Everything fits great now!

TL;DR:
13/64" drill and 6mm backing washer