Mitch.
The Handi platform is not a good canditate for an AI.
Due to the elastric stretch in the action cases don't last very long, so you be
forever fire forming brass.
In order for the rifle to behave, the pressure in a Handi needs to kept down to
about 54ksi lest the underlug upset. Well with the extra powder in a 280AI you
don't have much to show for.
In a strong tight bolt action the 280AI can be loaded to 65ksi and it is with bullet under 150gr equal to the 7mmRem Mag.
I had four of them and the last one got run over the barrel by a truck. Got a new barel but it was a lemon so I sold it at a big loss.