It would be far easier to inlet for a floating barrel, than to hand fit to achieve proper bearing, and military barrels were never packed with cork.
Never packed with cork? I always thought they were. Was it only target rifles that were packed then?

Inletting the barrel channel for floating may be easy but bedding the action for free floating is tricky - remember they didn't have epoxy bedding materials like we do. Clamping the action down onto the bedding with the bottom metal is tricky too, even with epoxy bedding. Also, the fore-end has to support the barrel when the bayonet is mounted. Mind you, more modern battle and assault rifles had no barrel support.