I have a build on a White Oaks 20” varmint in .223 Wyld that is a hammer, but even with CF stock and hand guard it is not light. It does shoot lights out though!
I use my Ultra 7 with the Diligent Defense HUB direct thread adaptor.
https://hansohnbrothers.com/shop/diligent-defense/accessories/mounts-and-pistons/diligent-defense-titanium-direct-thread-adapter/
If you know the fella you may want to ask what reamer he used, but I don't think it is that uncommon. Click the link to Accurate Shooter
https://forum.accurateshooter.com/threads/enlarging-brass-flash-hole.4079010/