Re: 338 Sin
Sounds very interesting as I have a Stevens .308 build in the pipeline. Might be a fun switch barrel proposition.
I have also been tinkering with an idea for a sub sonic .338 chamber to fit a short action/AR10. So you have a big heavy pill going sub sonic, maybe extend the accurate range of subsonic ammo. Your case might be a good prototype.
"Let glorious acts more glorious acts inspire,
And catch from breast to breast the noble fire!
On valour's side the odds of combat lie,
The brave live glorious, or lamented die;" - Iliad, Book V