I have an idea , ( scary thought i know ) but how about a semi-custom shop were you could order a frame , stocks and barrel all in one shot . it would be the same as sending in a frame but with out the hassle of having to wait to shoot while your frame was away .
They could stick with stock barrels and ship it to your FFL same as a new rifle . I don't see were it would cause anymore headaches than trying to keep track of whos frame is whos .
stimpy
I would love this. Posted about this in the 17 Rem Fireball poll. They could even keep the requests to barrels that are not on shipping rifles (ie 357 Mag, 17 Rem Fireball, but not 30-06) so they won't impact their re-sellers.
Think about being able to order up a custom matched set

--Carl