I doubt it is a chamber problem. I once sent a T/C, TCR barrel back and it was not the chamber. It was my reloads and the brand of brass I was using. Lapua brass and a neck sizing die solved my problem.
Hornady makes ammo to shoot in different rifles from different manufacturers with chambers cut from different reamers. In order to do that, the ammo is at the minimal tolerance of the SAAMI specs.
If your ammo is at the minimal end of the specs and the Pro Hunter chamber is in the middle of the road or even a bit toward the maximum spec, then you add a hot load, the brass will stretch more. Your Encore probably has a tighter chamber and the case did not stretch. I'm sure that two barrels were cut with different reamers even thought they both are T/C. Every rifle has its own personality.
Your reloads even if full length resized will not be sized to the minimum SAAMI spec like a factory load. Therefore the brass did not strech as much in the Pro Hunter chamber. Incidently a small base die will size the brass to a tighter tolerence to feed better in a semi auto. A small base die still doesn't size the brass as tight as the factory does.
I would suggest trying a different manufacuter's load or even a non magnum load before I would go accusing the manufacturer of the rifle. Reloads would be another option.
Something to consider,
Stan
