Re: When will I need to change my load?
In my view, cans could be redesigned to nearly eliminate additional length, at the cost of some O/O the box thinking.
The muzzle might be configured as something somewhat like a Garand Gas Trap (initial Garand version, only somewhat elongated, to provide some time delay), being ducted into a can which is underslung rearward beneath the barrel, routing the gasses rearward through the can, and then forward again to re-exit through the same trap once the projectile is clear. Taking this a stop further, this can could also serve as somewhat of a barrel support/stiffener, something like a barrel sleeve, but underslung, and could also serve as a bipod/accessory mounting foundation. And the underslung configuration would not intrude into the optical axis. With proper heat insulation, it could become a substitute for/with the same ergonomic purpose, as a stock forend.
But my ideas seldom catch hold...
Greg