No doubt they had the barrel in their inventory and just needed to turn it to your specs.
I got a barrel from Brux a few years back in a week after I confirmed the order.

Even the 250 gr Cutting Edge didnt work well in my 10 twist 338, yet both the Berger and SMK 300s both do.
My son has a 9 on his 338x378 and they work well in that also as do the 285 Hornadys.
C E dosent play mind games with customers by posting BC numbers on the boxes.