Originally Posted by Hawg Haggen
What will happen is you will lose the sabot in the forcing cone and the undersized bullet will go rattling down the bore like a golf ball in a sewer pipe and probably leave the sabot in the barrel.
The chambers are smaller than the forcing cone.
With powder exploding behind the undersized sabot, there should be plenty enough pressure to push the saboted bullet through the barrel.
A thin card can be placed behind the sabot to contain even more of the pressure if necessary, and even the hollow base of the sabot can be cut off.
I haven't measured my .36 rifle sabots to see what their overall length is.
But they could be trimmed at the back or front to make them shorter.
They are typically used with .311 - .314 bullets which could be paper patched etc, to fit even tighter in the sabot.
The whole load would be moving forward together, and I believe that plastic would offer less resistance at the forcing cone than a lead conical.
It would be an interesting experiment to see the results of on a target and what would happen.