The biggest obstacle might be the liner/sleeve walls circling the removable breechplug face, which I'm sure has to remain tightly edged. Like all breechplugs, which must be changed-out on occassion.

Oops, I just thought of something. That darn QLA......
Didn't mean to hijack your nice thread. Carry-on and please mention me, next time you and the barrelsmith talk.