Winchester Model 59 shotgun, circa 1960:
The Winchester Model 59 features technological advancements and innovations never seen before when it was released in 1960. A six-pound twelve gauge semi-automatic that is reliable and easy to clean proved it to be ahead of its time. There are no gas valves, inertia systems or complex mechanisms that make this gun function. A super-simple floating breach is the heart of the gun.
The floating breach consists of the chamber and forcing cone, however it is a separate piece from the barrel. Upon firing, the floating breach acts like a short piston and moves to the rear about 1/10 of an inch. That slight movement sets the bolt into rearward travel under its own momentum. A return spring pushes the bolt forward again where it picks up and feeds another cartridge.
The innovation does not stop there. The barrel is ultra light-weight. It is a metal tube that is wrapped in over 500 miles of fiber thread that fused and bonded. This process is similar to the carbon-fiber barrels that are increasingly popular on rifles.
It might also be possible to use a ceramic/glass composite inner *base tube* rather than metal. Composites and ceramics have come a mighty long way since 1960. Remember that early muzzleloading rifles used Damascus barrels made by forge-welding three bars of metal radially around a mandrel.
I recall reading somewhere the Army and Navy were interested in the concept of ceramic barrels for the big guns, 20mm and up.
I couldn't find any recent info on how the research was progressing but here's a couple of links on the subject:
APPROACHES FOR THE DESIGN OF CERAMIC GUN BARRELS
Advanced Ceramic Gun Barrel Materials & Processing Methods--Phase II
Eventually we'll see an exotic ceramic barrel, just a matter of time.